MTN robbing me of my hard earned income

MTN is probably one of the worst companies in South Africa to do business with. Very easy to take out a contract at any of the numerous branches. The term of my contract came to an end and I wanted to cancel my contract. I first phoned MTN. They told me that I must go to a branch to cancel the contract. I then went to the MTN branch in Ermelo. The lady was very rude and impatient and told me that contracts can not be cancelled at the branch and that I must phone MTN. I tried phoning them twice, but after 30 minutes of holding the line I gave up. Today I phoned again and eventually got through to a lady. She gave me a reference and told me that she is putting me through to another department that will cancel the contract. I held the line for another 20 minutes after which the call was dropped. Needless to say that the matter is still not resolved and MTN will once again rob me of my hard earned income at the end of the month for a service that I am not using anymore.