Disgusting service given by MTN

I will never recommend dealing with MTN. I cancelled a contract at the beginning of 2020 and was assured that it was cancelled. MTN continued debiting my account which I reversed (and was in my right to do). I called them to enquire what was going on and was assured that the contract was cancelled and it was in order that I reversed the debit. I have now received a notification that they have gone and added a default onto my name with transunion for R280 which - according to them I owe. My contract amount was for R49pm - so I am not understanding the R280. Also, in the nearly 3 years I had the contract, I never once received an invoice or statement from them nor when I requested cancellation was I advised of any amount owing. I find this action taken by MTN to be in very bad taste and in no way treating a customer fairly. To crown it all no one can get hold of a customer service agent to discuss and resolve as MTN has made it impossible to speak to anyone - I am guessing due to COVID but that is no excuse when other cell companies are easily accessible and willing to assist with any or all of your queries. Shame on you MTN! I am one very dissatisfied customer who will NEVER recommend your company!!!!!