Incorrect billing - Breach of contract

January 2015, we changed our DSTV standard premium package to the new Xplora 24 month contract whereby we should pay on R799 for the next 24 months. We were told that our premium would not increase for the next two years. On the 2nd March we received notification that our premium would increase on the 1st April 2016. We sent an email back on the same day querying this increase because 24 months have not passed yet. We received no response. I phoned Dstv a couple of days later and was told that there is no indication anywhere that I have a 24 month contract or that I have a Xplora decoder. I was also told that they moved to new computer systems last year Juky/ August and that information had been lost. I was promised feedback, nothing happened. I phoned again on the 15th March, received the same information and was promised feedback by Thursday 17 March, still nothing happened! I am considering cancelling my contract with DSTV!