Contract Cancellation

I am trying to get out of a contract I have with cell c because it makes no financial sense to me anymore. I've called the cancellation department they sent me to the bank to deposit the cancellation fee, the first consultant tells me to wait 24 hours, the next day I'm told its now 48 hours. Trying to call after that I end up on the waiting tone. I went into the store at Newtown Mall and they told me they don't cancel in the store and that they see no request of me cancelling the contract. This is frustrating because I've made it clear that I am not interested in upgrading or continuing with cell c any further. They keep postponing my request until I have to be billed again the next month. I am not happy with this service.