Month to month MTN ****

I took out a month to month contract with MTN on 5 October 2024 for a Free to Use Router with Home Internet LTE for R429 pm. When I took out the contact on their website I had to make a payment to finalise the order, being prorata for October plus November premium paid in advance R802. However on the 5th November I received a statement stating I'm owing for October, November and December and was debited on my account for these months, despite already paying for October and November. I made numerous call and sent numerous emails to MTN and even went numerous times into the branch but all these efforts failed as they insisted they did not receive payment. I had my bank reverse the debit order until the matter was resolved, and it wasn't. On the 25 November the internet service was stopped by MTN despite me paying already for the full month of November and I duly returned the router to MTN. IRMS cancellation reference number received from Oval Ladysmith MTN is ***. Upto date I am still being billed by MTN even upto the month of January 2025 despite not having any service from 25 November and despite canceling the so called month to month contract. I had repeatedly sent numerous emails including proof of payments, bank statements showing payments to MTN and have still not received feedback but generic messages saying my payment can't be found at that the contract is not cancelled and that I am owing money to MTN. Besides MTN service issues what is really irritating and frustrating is their service in resolving a simple issue.