NETCARE ACCOUNT IS PAID UP AND STILL GET CREDIT BUREAU LISTING LETTERS

Good day, I have the same problem with a account that is fully paid up. I received a letter about reporting me to the Credit Bureau Listing. I received this letter via post by a Amanda Khaynyile email address ********** is was a netcare account that is paid up in full.... we actually overpaid them and they refund us the overpaid amount. I phoned the number on the letter ********** 813 stating the mailbox is full... what are our legal rights regarding such a letter. I cannot get hold of the Amanda. Can someone assist with this. Is this just a **** ???