Cell C theft

I took out a new Cell C contract in September and they delivered the phone but not the sim card. After much calling to their call centre numerous times, they eventually sent me a defectivr sim card in November. When I called again, theyntold me to go to a cell c store and buy another sim card. I refused! The issue was not my fault and I didn't see why I had to go through the cost and effort to rectify their mistake. They have continued to debit my account since September but have not provided a service. Everytime I call the call centre, I get told that it will be noted and and escalated and nothing happens. I am really considering going to a police station and lodging a case of theft and cancelling my debit order. Cell C - do you have any further response beyond 'it will be escalated'?