Dont take up a contract with MTN - You will be here too

I am extremely frustrated with the cancellation service provided by MTN. I have been struggling for days (still am) to obtain confirmation that my contracts have been canceled, despite scheduling and paying for one of two contracts over two months ago (the other reached its end of term). To my surprise, I have recently received an invoice for substantial amounts of money that they are unable to explain the origin of. This situation is utterly ridiculous. I have visited their branches and called their call center multiple times, but no one seems to be aware of the issue or knows how to resolve it. I would never recommend a contract with MTN to anyone. This is truly shocking!