Billed me for a contract I do not have

I was told that I could RENEW my existing contract, only to find out they were tying me into a new contract that I did not want. I managed to cancel it, but my bank account has been debited with R1473.08 on 25 August, when my normal bill is around R550, almost an extra R1000, and they will not tell me what it is for. I have tried calling the number, emailing, no answer, only the automatic responses. The invoice is VERY confusing, and there are TWO of them! My line was blocked from 23 July, so it is not over-use. <br> The service that I have received from MTN is absolutely DISGUSTING. Not one person that I dealt with took responsibility. I want a written response. Not lies that I will get told or handed from one person to the next if I phone the 808 number like they keep telling me.<br> I have cancelled this contract, and as soon as my data contract is up in November, I am cancelling that too.