All want is for MTN cancelations to do their job and cancel my sim contract. Sounds simple but it is not!

I have twice paid early term fee as per email instructions from MTN retentions but continue to receive email requests from retentions for the same info that I have already sent (including both early term fees). I have asked in my emails to please advise me by email to advise me the contract is canceled and all I get is another email from another agent asking for the exact same personal details. Initially I called the call centre and chose the option key for retentions. No answer. YOU DONT GET TO SPEAK TO ANYONE. I ASK YOU TO TRY IT YOURSELF. YOU WILL BE GIVEN SOME MINUTES OF ADVERTISING THEN THE PHONE GOES DEAD. AND THE CALL ENDS. THIS HAPPENED WHEN I FIRST TRIED TO CANCEL MY SIM CONTRACT. I TRIED AGAIN recently AND THE VERY SAME OCCURRED. TOTAL OF 18 EIGHTEEN EMAILS BACK AND FORTH SO FAR . On Thursday I sent a complaint with a copy of all my email correspondence thus far and still no email advising the contract is canceled. I did receive a voicemail today that was totally inaudible. Not sure what to do with that since I can't access a person at retentions, one, because their phone lines cut the call, and two, I can't send my email to a person. Someone did in fact speak to me and said she would watch my account for the early termination fee I paid, but since then I have received more emails asking for my ID and other confirmation info. So still going around in circles, and paying for the contract by the way which hasn't been active for months now so it's money down the drain. all I want is a letter confirming that this sim contract is canceled.