Disgruntled former customer

I took out a student loan in 2009. The loan was then paid off by my mother and we thought that was the last we heard from Standard bank. Fast forward to 2015 I keep getting SMS's from their lawyers claiming I owe them R800+. I then went to Standard Bank Protea Gardens to follow up and confirm if indeed it is my account. <br> <br> First thing Nomsa said to me is they (Protea Gardens) wont be held response or clear the debt as a fault of their as they don't know how the account was opened. I then questioned that as I took the loan in 2009 at their branch. I went on to ask why was the account in arrears she then said the student loan was paid off but the account linked to it was still active and there was a company making monthly debits to the account hence it went up to the money owed. I asked her to log a complaint for me and give me a reference number, she said the center was closed as it was a Saturday. The best she could do is call the lady who activated the account as she knows who she is and she will get back to me. The whole of April I haven't heard from them. <br> Its disgusting that banks hold us ransom about false accounts then advise us to pay because it will hurt out credit score