RCS says I owe them - I paid them in full

I had a loan with RCS which I paid for in full on the 2nd of July 2015 - I paid R7649.90 but I keep on getting sms's that I owe them R876.92. I have called them previously to advise them that I don't owe them anything and I was told to call the lawyers which my account was handed over to. I called the lawyers and they said to me RCS needs to update their records because they do have proof that I have been in full and that I am not owing anything.<br> <br> Today I tried calling them after receiving an sms that I owe them I waited on the line for more than 10 minutes without anybody picking up my call.<br> I eventually hung up.