Don't ever sign up with Cell C

My wife opened 2 contracts with this network we had both for 2 years never missed a payment to a point we paid over a R 1000.00 per month at some point we even paid for services added which we never asked for. Yet we continued with the contract. Now it has come to the end of our contract and we are suppose to call in to cancel or stop the contract, but we do call all the time and when the person on the other side of the hear that we need to cancel the contract they switch off the phone. What is up with that....I can't believe a multi billionaire company would want to rob people like us....people that has been supporting them for 2 years without failing them...how can they be failing us rite now???