MTN don’t want to cancel my contract

I took a WiFi contract with MTN and went to cancel it the following month because I was not happy with the service. It’s 7 months now without them cancelling it. Whenever I go there they tell me the manager is not there or he’ll call me and the lady that helped me to take the contract, when she sees me she runs to the back till I leave the store. MTN at West Gate is the worst with costumer service