Terminated Contract, Still Getting Charged

My contract was terminated on the 27th April 2015 with Altech Autopage, my bill for that month was R2157.34, I was told this was correct, however I had to requested billing information, it was just deducted and not sent to me. I still want to know how it is possible that my bill was over R2000. Then in May I received another invoice for R1053.29. How is this possible when I no longer use your service and at this time I was already on prepaid airtime. I called and was told this would be the last deduction. It still makes no sense to me how money is still being debited from my account for a contract which ended! Today on the 08/06/2015 I received another bill for R23.67 ? What is this for? Can someone please escalate this as a matter of urgency. I have just gotten off a call with your customer service employees and he says he has logged this with accounts. I can't wait for another invoice. This needs to be rectified NOW and I need to be reimbursed accordingly! The invoice ref is ***<br> <br> Thank you