Horrible service

My contract has reached its expiry date and I contacted MTN on 21/10/21 and gave them am official request to cancel this contract. I was told they are off line my details were taken. Did not get a call. I sent an email to their complaints dept on 26/10 and they responded on 30/10 stating they will ref the cancellation to the correct dept. No one called me. I called again and sent a reminder email to complaints no response. I kept on calling they promise to call back and no one does. I sent another email this morning. I called and was told the contract is not cancelled. I m not certain what to do to get someine at MTN tp do their job and cancel this contract effective 10/21.