Charging paid up account

Do not ever use their services, they will ruin your credit record. I got a credit card from RCS and I settled it in June 2020. I asked them to close the account and I also got paid up letter. To date it's appearing as if my account with them is in arrears with R382 ( the amount increases every month). I called and sent emails begging them to sort out the error they are not doing it. If they not transferring me from one department to another or telling me it's sorted out and it will officially clear. Long story short the account is still in arrears and affecting my credit score. They just **** these ones.