Paid up letter

Cell C what does it take for one to get a paid-up letter from you, I have been in contact with you since November 2021 to date I still have not received the paid up letter, I have lost count of the number of calls I made to you as well as the emails I sent to get told of the 48hrs turnaround time to date the matter is still not resolved. what does it take to get a paid-up letter from you? What makes this whole thing worse is that I am suffering from a contract that ended in December 2020 and you continued to bill me for a contract I terminated. all I want now is the paid-up letter so I can clear my name from ITC