terrible contract service

My data contract with Vodacom expired in August 2015 after two years. At the end of my contract the usb data device did nt connect to the Internet anymore as it did before so I assumed it was because my contract had ended. Vodacom continued to deduct the debit order from my account even tho I did not receive my 3GB of data per month. I called the call centre on 16 September to clarify the situation as was greeted with a lackluster explanation by the call centre agent. She said that vodacom continues to debit on a prepaid basis after your contract expires, without your knowledge in most cases. They transfered me to cancellations department where they said my device maybe damaged or my sim card is non functioning. They said that my data should be still on the sim card but if I cancel the debit order it erases my number and all my data with it. So I have paid for nothing for two extra months while vodacom has gained heavier pockets. I did cancel my contract and feel as though I have been ****** somehow. I am not happy with the level of the call centre agents and how they handled my situation. I will not take a contract out with Vodacom again and will voice my negative experience.