Handover of accounts

Hi<br> A few years ago i had a student account and had it closed because there were charges incurred i was not informed about when i opened the account. The account was overdraft with over R1000. Since then i was never contacted until after about three years. A lady called saying standard bank has handed my account over to them and i should pay 1500 to avoid legal action. I am not sure whats happening as i was not aware that a student achiever incur costs of 1500.<br> Please assist as i do not know what to do.