NO HELP!!!!!

Plus minus three months ago, the Cell C call centre phoned me to sell me a new contract because mine expired and was on a month to month at the time and with the new contract I would save money and its a better deal. I agreed and on a Friday they delivered a new sim card and ****le to me. I got off work at 6 PM and as soon as I got home tested it. It did not work and the next morning I went to Centurion Branch for help, they said I must deal with the call centre because they did the contract. Since that day we realised that the ****le did not work, I asked them that Monday after I received it to please cancel my contract or give a new sim and ****le, but still 3 months later no help was given and we use the old card but pay for something that we can not use and can not use any night time that we paying for. All I want is URGENT HELP FROM SOMEONE WHO KNOWS WHAT THEY DOING. I find it unfair that if I want it cancelled that I must still pay a amount after they don't want to help.