Contract not cancelled after multiple requests

My contract still has not been cancelled despite multiple requests with MTN. I went to the MTN store in Fourways Crossing to cancel the contract at the 2 year anniversary (i.e. end of the 2 year contract) on the 31st of July 2015. The cancellation form has since then been sent multiple times to MTN. At this moment in time (4th of September 2015), it seems my account is still active and I'm still being billed..<br> <br> The promise of a response within 3 business days is not very accurate.<br> <br> Communication references: #***1, #***0, #***3.<br> <br> <br> Please advise how I can close my contract as the default procedure does not seem to work.