24 MONTH CONTRACT BECAME 32 MONTH CONTRACT

My contract was taken out at Game stores and it was suppose to be for 24 months, June 2014 I received my monthly statement with state that July will be my final monthly instalment, July I received my statement stating that the amount of R0.00 is owed by my as stipulated on page 2. I am being debited up until now R215.00 p/m I can stop the debit order at my bank with no luck it is just being deducted again and again. Now I am being told that they decide to extend the contract by them selfe on a month to month basis, I am suppose to call them on the 23rd month to say that I no longer wish to make use of their services. Why does it state then 24 months on the contract. The call centre lady who assisted me today said that I am suppose to read and re-read my contract and the fine print that it is stipulated I must go and read it up. When I asked to speak to her team leader she said \I know the procedure