Unhappy with MTN

So I signed up for a contract at the end of August 2021 with a LTE router from MTN, got the device and sim card delivered to my work. The device was not working and I was no longer happy with MTN and their services. I returned the not working LTE device to the MTN store in Pavilion Westville. I have phoned the MTN number to cancel my contract several times, when you phone the MTN customer care number there is no option for you to choose to cancel your contract and even if I did get through to someone after 1 hour on the call waiting for someone to answer- they were not able to help me cancel my MTN account. MTN keeps debiting my account 1st of every month even though I have put a stop order from my bank's side.

I am very unhappy and BEYOND disappointed with MTN and their services and even the level of competency even when you do speak to someone in customer care.