RCS Account unending payments

I have settled my RCS account on the 26 of April with MBD corporate.i received a paid up letter from them, but they did not update with the credit beraeu. Then I logged a dispute at transunion. Then I was assisted and they cleared the RCS account of my report. Then 3months later I receive an email from Daly corporate that I'm owing R1788. 20 for my RCS account. I tried explaining to them and also emailed my paid up letter to them but I'm still receiving mails and annoying phone calls day and night. I dnt knw how I can resolve the matter because I can't pay RCS my entire life. Pls assist