Incorrect Bill & Misrepresentation of Facts

I wanted to migrate to a prepaid contract following expiry of my contract this year in May. I called MTN and spoke to Jeetendra Chiba on 1st June 2015 who after asking why I want to migrate to a prepaid contract and while we spoke I was convinced to upgrade on my phone, that is, I didn't get a new phone. He promised me this one will be cheaper, and that he will offer me a once-off free R1 000 airtime, and said that with this one I can cancel it anytime if i am not happy. I told him I wanted top-up and he said I must call MTN and set a zero limit so if the R200 airtime is finished I can buy myself airtime. I agreed and to my surprise by August 2015 an amount of R1127.21 was debited even though I had been buying airtime. I called MTN and spoke to many people who couldn't give me the reason why and that's why I called being irate and asked that my contract be terminated and that's when they were quick to tell me that there is a charge to cancelling the contract earlier. I asked them to listen to the recorded conversation between myself and the agent (Jeetendra) because he promised something else but they are not keen. One of the many references I was given is ***5. Need recourse.