Bobipex,
If I understand, you had a credit card at Bank A which you did not repay. Now, you have gotten a call from your current bank, Bank B, where you are being encouraged to repay Bank A.
Thats unusual. I can only thing of two reasons Bank B would do that. 1) You have a pending credit application at Bank B. Since you did not mention a pending application, the more likely possibility is 2)Bank B is reviewing your account to see if you still qualify for it.
You have the right to ask what prompted the inquiry and, if you are upset about it, you should call the bank and ask to speak to an officer who could explain it to you. However, if you do business with a bank they are entitled to ask you questions regarding your past credit history, whether it's on the phone, in person or in the form of requiring you to fill out an application.