Unable to cancel contract

I've had a data sim card with MTN for some time. The contract period was 2 years and this has long passed and I wish to cancel the contract and stop paying the monthly fee. I terminated my first 3 calls (over a period of about two weeks) to their callcentre after holding for 20 minutes each time while paying mobile telephone rates. The 4th call was answered, I received a ticket number and was assured the cancellations department would contact me within 2 days. That was a week ago. <br> <br> MTN makes it impossible to cancel expired contracts! Already the difficulty I've had contacting them and waiting for their response means they've taken off another month's payment from my bank account. <br> <br> My notes are a bit of a muddle, but I think the ticket number is 127 553 265. <br> <br> Contact me MTN, refund the final payment you took off and cancel the contract! <br> <br> I strongly recommend to all data and cellphone users that you avoid MTN.