MTN call-centre ******** contracts

My contract was due for an upgrade, they kept calling me and I said I don't want an upgrade. Then they called me again and said I could be paying less for more than what I was getting and didn't tell me this was another contract. When I finally decided to get an upgrade I was told I was actually in another contract and would need to pay R270 to cancel that upgrade. The lady who was helping me at the store told me that the call centre people actually do that and there is whole list of people who have lodged similar queries which have not been resolved.