Cancellation of contract

My device subscription ended in April and I have been trying to ever since to get it cancelled. The MTN branch cannot assist and have referred me to MTN retentions department which I have tried to call on several occasions but to no avail. After several visits to the MTN store, I was provided with an email address that I could use. Sent an email 3 weeks ago and got an auto response stating that termination of contracts must be done telephonically and that an agent will be in contact with me. Waiting since....