Cell C contracts are not transparent

Cell C contracts are not true... I upgraded my contract because I was told I can cancel it anytime because the is no asset that is attached to it. Suddenly when I want to cancel it I'm told of R4000 rand that I have to pay before it can cancel. They said the policy were changed. 1st of all in didn't agree on the policy and it was not part of the contract I've agreed on. Can I please get help I don't want this contract anymore. I don't have any asset that can bind me to stay. I feel robed

Kind regards Mmangwato