Bad and *********** agents

I have paid off the account last year and I called the call center to get a paid up the letter, and to also report to transunion to be able to update my credit record, to my surprise 5 months later I am still owing Onair R119 and it affects my records I want this fixed ASAP..... I did not want to come to this platform but it left me no choice as they no longer pick up my calk