contract cancelled after 24 months

My contract started on 17 October 2013 and ended 17 October 2015. I sent a letter to Jillian and Clive at the Centurion branch that I want the contract ended on the specific number ***. The other number on the account is still in use. The contract is still running and money is being deducted every month for that number. How is that fair? I ended that contract. The sim card is not in use and has not been in use now since August 2015. As far as I am concerned this is theft! I want a complete refund for the amount of calls I had to make, for the inconvenience and the plain disrespect from your company and call centre staff. I want my money back as this is theft I have no choice but to lay a charge of theft at the sapd.