Cancellation of contract nightmare

I took a month on month contract with MTN as I was not looking for a fixed contract for years, I was assisted with a month on month contract which worked for me. I experienced a lot of problems with the service provider of which most if not all resulted in being unsolved :( , I gave the company countless chances thinking things would take a good change however instead it got worse and worse by the day. When I called them for assisted they would transfer me from pillar to post with no resolutions, in some cases they would just hang up the call on me. It got to much for me after months of trying to make this relationship work, until I decided over a week back to end this toxic relationship which was not working for me and protected my peace, that’s what I thought only for my problems to get worse. I call customer care and was advised that I can cancel the contract I would need to take the router to the nearest MTN store and I will be assisted in completing a form of return on the router, I went to the first MTN shop Middelburg Mall on the 19 July 2025 and the consultant advised me that they won’t be able to assist me as I need to produce proof of purchase, mind you I had that router for months if not years and can’t recall weather I was given proof of purchase invoice when it was delivered, I am human after all and I might have misplaced it, I then advised the consultant that is not what I was told when I call their customer care line to cancel the month on month contract. The lady gave me a number to call and said “maybe they will assist you, I left the shop when I got home to call that number onlu to find out that the number does not exists :(. So clearly I was given the wrong number on purpose, I then had to drive back again over 35 kilos for the second time in a day when I got there I was told ohhh maybe it’s because is Saturday and I asked the lady then why would the number say it dsnt exist. She had no answer, I advised her that I called customer care and they said I don’t need to submit any invoice only to complete the form and submit the router. The lady said sorry we don’t be able to help you. I then left and call MTN they advised I need to go back I went back and same thing happened again I was not assisted. I am extremely disappointed with MTN as I see what they are trying to do, to keep me on a contract that I no longer need. Why is so hard for them to accept that o no longer need their services