I cancelled 2 contracts and am still being billed

I am beyond upset at the incompetence of Cell C. I had a contract for two data contracts. The contract expired and I was on a month to month payment which i was not even informed about. I phoned Cell C in April to CANCEL these contracts but they are still billing me. They allegedly record all call but cannot find the call where I requested the cancellation. I am still being billed. I have spoken to several different people and have not been able to have this resolved. Finally they managed to cancel the one contract but i am still being billed for the other contract because THEY DID NOT HEAR WHEN I SAID I HAVE TO CONTRACTS that i wish to cancel !!!!!! i Requested to speak to senior management but even this was mission impossible. Hopefully someone can contact me and sort this out once and for all !!!!