Data Cancelled by MTN

Hi,<br> <br> I have been an MTN customer for many years. In November 2013 I upgraded and signed a new contract. The new contract included 350mg data and an additional 150mg data to last the term of the contract. After getting my data for over a year, I was sent a message by mtn on 30 January 2015 to say that my 350mg data bundle had been cancelled. Since then it has just been one long nightmare. I have sent messages on their website. I have emailed. I phoned the customer service centre, where I was told that I must prove that I was entitled to get the 350 mg data. On the last of the numerous calls to the call centre I was told that I would have a response in 7 working days....and of course, there has been no response.<br> <br> My latest account reflects that I owe mtn money for data usage!!!<br> <br> I would like to know if I can cancel this contract immediately and port the number to reputable network, as MTN is clearly in breach of contract and has no intention of addressing the issue. <br> <br>