MTN

I've had contracts with MTN for the past 16 years. At the end of term on the last contact, I have decided not to upgrade and go to another service provider. So I gave notice to MTN to end the contract (which was about to end in anycase). Upon hearing that I don't want to upgrade, I was contacted by an online MTN sales consultant, and was told how MTN has changed for the better, with better service etc. Against my better knowledge,I upgraded with MTN a few days later. New contracts and new devices. 30 days later, MTN decide to cancel the new contract and charge me R24 000 for contract cancelation. After explaining to them that they cancelled the wrong contract, I now pay R5600 per month for a pay as you go phone. The R24 000 cancelation fee still pending and no word from MTN. Am I entitled to open a ***** case against MTN?