Managing Credit Card account

[trex123]

Ok, so what I have to do is Make a program to manage records for just one credit card account.
The user is able to setup the account, choose payment date, choose the APR, choose payment day, choose late payment fees and overcharge fees. He is also able to make charge transaction and able to make payment.
The place where I am stuck at is I can not figure out how Can I get the User to make payments and charge the account.
I do have two different files for both.
They are as following:
For Charge transaction

#include <iostream>

main() {
 /* access file, gets Transactions */
    ifstream fin("creditcardlog.txt");
    if (fin.fail()) {
        cout << "creditcardlog.txt not found!\n";
        exit(1);
    }
    string lineone;
    fin >> lineone;
    fin.close();

 /* Transaction(char, unsigned long, string)
 */
    char transactiontype = 'c'; // transaction tyoe
    unsigned long moneyamount; // money in pennies
    string payee = "Blank"; //payment description -   29 spaces

//get moneyamount in pennies, not to excede 0 to 4294967295
//get payee info (business)

 Transaction::Transaction(transactiontype, moneyamount, payee);
    return 0;
}

And for Making Payment:

#include <iostream>

main() {
 /* Transaction(char, unsigned long, string)
 */
    char transactiontype = 'p'; // transaction type
    unsigned long moneyamount; // money in pennies
    string payee = "Credit Card Payment"; //payment description -   29 spaces

//get moneyamount in pennies, not to excede 0 to 4294967295
//get payee info (business)

 Transaction::Transaction(transactiontype, moneyamount, payee);
    return 0;
}

I have been trying a lot, can not seem to get my head around it.
Any help/suggestions/code/answers will be great.