Reading from and writing to a data file

Ok guys the follow code I am trying to read from the file!
Add 2 New Accounts
Then modify One Account
Then Write everything back to the file!

Can someone please help me...it does not work and I am getting this error:

Code:

#include <iostream>
#include <fstream>
#include <iomanip>
#include <functional>
#include <algorithm>
#include <string>
#include <cstdlib>
#include <sstream>
using namespace std;

//Account class
class Account {
private:
	int number;
	double balance;
	double rate;

public:
	Account(); // Constructor
	Account (int, double, double);
	void setNumber(int);
    void setBalance(double);
    void setRate(double);

	int getNumber();
    double getBalance();
    double getRate();
	void account_details();
	string string_account_details();
	void account_Readdetails(ifstream &in);	
	void Account::account_details(ostream& out) {
	out << number << " " << balance << " " << rate << "\n";
	}

	
};

Account::Account()
{
	number =0;
	balance = 0;
	rate = 0;
}

Account::Account(int number, double balance, double rate) 
{
//this pointers to the current class
        this->number = number;
        this->balance = balance;
        this->rate= rate;
}

void Account::setNumber(int number) {
    Account::number = number;
}

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

void Account::setRate(double rate) {
    Account::rate = rate;
}

int Account::getNumber() {
    return number;
}
double Account::getBalance() {
    return balance;
}
double Account::getRate() {
    return rate;
}

void Account::account_details() {
	cout << "The current account number is " << number <<
		" with a balance of $" << balance << " and an interest rate of " << rate << ".\n\n";
}
void Account::account_Readdetails(ifstream &in)
		{
			in >> number >> balance >> rate;
		}

Code:

#include "Account.h"
#include <iostream>
#include <fstream>
#include <cstdlib> // for exit function

using std::ofstream;

int main() {

	Account acc;
	ifstream readData;
	int tempInt;
	double tempDouble;
	int current_account = 0;
	int menu = 0;

		ifstream file("AccountDetail.data");
		if(!file)
        {
                cerr<<"ERROR"<<endl;
                exit(0);
        }
		acc.account_Readdetails(file);

		for (int x=0; x<6; x++) {
			acc.account_details();
		}

		//Add 2 new accounts
		for (int i = 0; i <2; i++) {
			cout << "Enter the New Account Number: ";
			acc.setNumber(tempInt);

			cout << "Enter the New Accounts Balance: ";
			acc.setBalance(tempDouble);

			cout << "Enter the New Accounts Rate: ";
			acc.setRate(tempDouble);

			for (int x=0; x<8; x++) {
			acc.account_details();
		}

			//Change Account Information

			         while (menu!=3)//keep going until 3 is selected
        {
        cout << "Vehicle Menu\n\n";                     //Menu
                cout << "1. Select the Account to edit:\n";
                cout << "2. Change the Account Number :\n";
                cout << "3. Exit the Program:\n\n\n";

        cout << "Please choose one of the above options: ";
        cin >> menu;
        cin.ignore();
        cout << "_______________________________________________________\n";
			 //switch begin
        switch ( menu )
                 {
        case 1:
                        //Here the user will select which Account to edit!
                        cout << " Pick a Account to edit\n";
                        cin >> current_account;
            --current_account;
            cin.ignore();
            cout << "_______________________________________________________\n";
            break;

        case 2:
                        //User will be able to change the Account Balance 
                        cout << " The Balance of the account is: " << acc[current_account]->getBalance() << endl;
            cout << " Please enter the change to the account: ";
            cin >> tempDouble;
            acc[current_account]->setBalance(tempDouble);
            cout << "_______________________________________________________\n";
            break;

			  default:
            cout << " Please restart the program, you have entered invalid information!\n\n\n";
            break;
		}
					 }

		for(int i=0; i<8; i++)
		acc[i].account_OutPutdetails(file);

		file.close(); // close file



		cin.ignore();
		cin.get();


			return 0;
		}

Error:

1>\main.cpp(71): error C2676: binary '[' : 'Account' does not define this operator or a conversion to a type acceptable to the predefined operator
1>\main.cpp(71): error C2227: left of '->getBalance' must point to class/struct/union/generic type
1>\main.cpp(74): error C2676: binary '[' : 'Account' does not define this operator or a conversion to a type acceptable to the predefined operator
1>\main.cpp(74): error C2227: left of '->setBalance' must point to class/struct/union/generic type
1>\main.cpp(85): error C2676: binary '[' : 'Account' does not define this operator or a conversion to a type acceptable to the predefined operator
1>\main.cpp(85): error C2228: left of '.account_OutPutdetails' must have class/struct/union

1>\main.cpp(71): error C2676: binary '[' : 'Account' does not define this operator or a conversion to a type acceptable to the predefined operator

You can't referance a single item as an array

1>\main.cpp(71): error C2227: left of '->getBalance' must point to class/struct/union/generic type
You aren't using a pointer so -> is not defined you MUST use '.'

repeat 2 more times.