MTN won't cancel an expired contract

I'm literally throwing up as I write this message because I just got another call from the debt collectors. I've been battling to cancel an expired contract with MTN the whole year now. My contract ended in August 2021 and I asked for my number to be converted to prepaid. This has not been done to date. Instead I'm being sent from pillar to post. I have been complaining since November 2021 that I'm being debited for an account that is supposed to be cancelled. I was then told that the reason it was not cancelled was because there was an outstanding amount of R234, which I must pay, then it would be cancelled. I paid the amount and sent proof of payment but the account is still not cancelled. I'm constantly getting emails and phone calls DAILY to make payment arrangements from <***>. My credit record is damaged because according to MTN I've been missing payments. I even wrote to MTN's complaints department *** and got a generic auto response promptly on the 29th of April. Did they ever get back to me? DOLOLO!. My next step is reaching out to every media house willing to listen to my story. Maybe then someone from MTN will finally notice.