Cell C customer care cancellations department not able to cancel for 3 weeks now

I have a cell c contract which expired and I am now on a month to month. I am struggling for three weeks now to cancel. First I phone and they tell me to go into the branch. Then I go into the branch and the lady tells me sorry you have to call in. I have been trying to call in and when they put me through to cancellations department the operator says the department having some technical issues. How do I cancel if nobody wants to assist but I will just have to Continue pay because Cell C is not cancelling ??