How can I update a mutator (Setter) in a class? (C++)

I want update the balance after the user enters a new deposit amount. When I enter a new amount the balance remain the same. For example, the user can have 2000 as the balance, If the user wants to deposit an extra 1000, it should add the two and display 3000 as the balance, but I only get the original 2000. How can I fix the code so that it can update the balance?

I have three files;

Account.h

#pragma once

class Account
{
private:
    int accountId;
    double balance;
    double annualInterestRate;

public:
    Account();
    Account(int id, double bal, double interest);

    void setAccountId(int x);
    // Function to set accountId based on passed parameter.
    // Postcondition: accountId = x;

    void setBalance(double x);
    // Function to set balance based on passed parameter.
    // Postcondition: balance = x;

    void setInterest(double x);
    // Function to set annualInterestRate based on passed parameter.
    // Postcondition: annualInterestRate = x;

    int getAccountId();
    // Function to set accountId.
    // Postcondition: accountId is returned.


    double getBalance();
    // Function to set balance.
    // Postcondition: balance is returned.

    double getInterest();
    // Function to set annualInterestRate.
    // Postcondition: annualInterestRate is returned.


    double getMonthlyInterestRate();
    // Function to calculate the monthly interest rate.
    // Postcondition: Monthly interest rate is calculated and returned.

    double getMonthlyInterest();
    // Function to calculate the amount that would be earned through monthly interest.
    // Postcondition: Amount that will be earned through monthly interest is calculated and returned.

    bool withdraw(double amount);
    // Function to reduce the account's current balance by the passed parameter, but only if the balance 
    // is greater than the passed in parameter.  If successful, return true, otherwise return false.
    // Postcondition: if (balance > amount) balance = balance - amount and return true;
    //                otherwise return false;

    void deposit(double amount);
    // Function to increase the account's current balance by the passed parameter.
    // Postcondition: balance = balance + amount;
};

Account.cpp

//*************************************************//
// Account class implementation, here is where the //
// header file gets info from the main //

#include "stdafx.h"
#include "Account.h"
#include <iostream>


Account::Account()
{
}

Account::Account(int id, double bal, double interest)
{
    int accountId = id;
    double newBal = bal;
    double newInterestRate = interest;
}

void Account::setAccountId(int x)
{
    accountId = x;
}

void Account::setBalance(double x)
{
    balance = x;
}

void Account::setInterest(double x)
{
    annualInterestRate = x;
}

int Account::getAccountId()
{
    return accountId;
}

double Account::getBalance()
{
    return balance;
}

double Account::getInterest()
{
    return annualInterestRate;
}

double Account::getMonthlyInterestRate()
{
    return annualInterestRate/ 12;
}

double Account::getMonthlyInterest()
{
    return balance * (annualInterestRate / 12);
}

bool Account::withdraw(double amount)
{
    if (balance > amount) {
        balance = balance - amount;
        return true;
    }
    else
        return false;
}

void Account::deposit(double amount)
{
    balance = balance + amount;
}

AccountMain.cpp

#include "stdafx.h"
#include <iostream>
#include "Account.h"
#include "time.h"
#include "iomanip"
using namespace std;


int main()
{
    //*****VARIABLES*****//
    int id = 0;                                     // id is set to zero to go into the loop
    int userSelection ;
    srand(time(NULL));                              // use srand and rand() to create the random values
    double accBalance = rand() % 10000 + 10000;
    double interest = rand() % ((15 + 35) / 10);
    double amount;
    //***END VARIABLES***//


    while (id != -1) {
        cout << "Please enter account number from 0 - 9(Enter -1 to exit): " << endl;   // Sets the id to the account number.
        cin >> id;
        if (id == -1)
            userSelection = -1;                                                         // userSelection is set to minus one to go into the loop
        else
            userSelection = 0;                                                          // userSelection is set to zero to go into the loop
        while (userSelection != -1) {

            cout << "Enter 1 to make a deposit" << endl;                // Ask the user for the amount they wish to deposit
            cout << "Enter 2 to make a withdraw" << endl;               // Ask the user for the amount they wish to withdraw
                                                                        // Return if withdrawal was successful or unsuccessful depending on function return value   
            cout << "Enter 3 to make a check balance" << endl;          // Display the account’s current balance
            cout << "Enter 4 to check interest rate" << endl;           // Display the account’s monthly and yearly interest rate
            cout << "Enter 5 to display account summary" << endl;       // Display account id, balance, monthly interest rate, and monthly interest amount
            cout << "Enter -1 to return to the main menu" << endl;      // This will return the user to the main menu prompting to select an account number
            cin >> userSelection;

            // Creates 10 objects of accounts.
            Account account[10];
            account[id].setAccountId(id);
            account[id].setBalance(accBalance);
            account[id].setInterest(interest);

            // Switch statement is used to properly engage each user choice
            switch (userSelection)
            {
            case 1:     // Ask the user for the amount they wish to deposit
                cout << "Enter Amount to deposit: " << endl;
                cin >> amount;
                account[id].deposit(amount);
                cout << endl;
                break;
            case 2:     // Ask the user for the amount they wish to withdraw
                        // Return if withdrawal was successful or unsuccessful depending on function return value   
                cout << "Enter Amount to Withdraw: " << endl;
                cin >> amount;
                account[id].withdraw(amount);
                cout << endl;
                break;
            case 3:     // Display the account’s monthly and yearly interest rate
                cout << "Current Balance: $" << fixed << setprecision(2) << account[id].getBalance() << endl << endl;
                break;
            case 4:     // Display account id, balance, monthly interest rate, and monthly interest amount
                cout << "Yearly interest rate" << fixed << setprecision(2) << account[id].getInterest() << "%" << endl;
                cout << "Monthly interest rate"  << fixed << setprecision(2) << account[id].getMonthlyInterestRate() << "%" << endl << endl;
                break;
            case 5:     // This will return the user to the main menu prompting to select an account number
                cout << "Account ID: " << account[id].getAccountId() << endl;
                cout << "Current Balance: $" << fixed << setprecision(2) << account[id].getBalance() << endl;
                cout << "Monthly interest rate: " << fixed << setprecision(2) << account[id].getMonthlyInterestRate() << "%" << endl;
                cout << "Monthly interest amount: $" << fixed << setprecision(2) << account[id].getMonthlyInterest() << endl << endl;
                break;
            default:
                break;
            }// END SWITCH
        } // END INNER WHILE LOOP (Selection menu)
    } // END OUTER WHILE LOOP (Main Menu)

    //*****DEBUG*****//
    //cout << endl << account[id].getAccountId() << endl;
    //cout << endl << account[id].getInterest() << endl;
    //cout << endl << account[id].getMonthlyInterestRate() << endl;
    //*****END DEBUG*****//
    return 0;
}