MTN refuse to cancel my contract

I have given a months written notice to MTN to cancel my cellphone contract. I received confirmation that MTN received my e-mails they even emailed back to ask why I was cancelling my contract and offered to upgrade me. I made it very clear u did not want a contract and wanted to be moved to pay as you go. Today I went to an MTN store at Clearwater to be told my contract had not been cancelled and that I first had to request to be moved to pay as you go then only could I cancel my contract, but I have to pay another month of contract fees. If I chose to cancel my contract today they would cancel my number. This is violation of my customer rights and I want to this contract cancelled imediately and to be moved into pay as you go today 2 November. I can't believe that MTN treat customers in this manner making it deliberately difficult for customers to cancel contracts.