Mtn is a cheat

I had a great relationship with mtn until this year 2020 after upgrading my contract during lockdown level 5. After the upgrade MTN started debiting money which was not agreed upon and no one took responsibility when i contacted them for answers. I went to one of the stores for assistance and no one could assist me. I sent emails, i called them with no positive response. I asked for a copy of the recording as the upgrade was done telephonically and still nothing.

All they do now is debit money from my account and am falling more and more into areas as they do not want to assist me.