BAD BAD Cell C service

On May 2018 we asked a contract to be cancelled. We are now a more than a year later and CELL C still charges us for this. We have phoned numerous times as well each time they tell us to an amount then it will be cancelled. STILL it doesn't get cancelled and we are charged all over again. No one can sort this out or help us. We are fed up with this bad service. The 2 year contract signed is long passed so its month to month. What can I as a client do. Attorneys? Publish it in the papers? WHAT??? because I am fed up with this bad service I need to pay for.