MTN home wifi

I have been contacting MTN for almost half a year to cancel my month to month home wifi with them that never worked properly since I got me the wifi. The route is useless every time I phone or go to MTN then they either say they are offline and that i should come back and when I phone they tell me to go in. I have been going round and round in circles with them raised complaints no one never gets back to me. I have emails sent to them. This month they took a whole R350 without even using the Wifi because the Wifi does not work