Resolve RCS outstanding amount Even Though Fully paid and contract Term is done

I took out a loan with RCS in 2014 for 60 Months. I have been paying this loan and I started noticing that my balance was not reducing though my last installment was due to come off in February 2019 and I got emails confirming end of contract term.

My issue is that I have an outstanding amount of R5200.00 which I don’t know where it comes from and I have been phoning the customer service to get clarity on where this amount comes from and all I get from the agents is they will come back to me and nothing happens. I have sent endless emails to: ********** and have never gotten any response. I get told our manager or supervisor will get back to but nothing.

I’m now getting SMS threatening me with legal action and being registered with the credit bureau.

To be honest with you I don’t mind paying but I just need to know where this outstanding amount comes from when my account is fully paid and my contract term ended this year in Feb?

I’m really getting desperate for assistance in resolving this matter