Inconsistent Debit Orders

I'm extremely disappointed with DSTV. I’m not sure how many more times do I have to complain about the same thing. They are so inconsistent with the debit orders, when I call to ask why I get told I was billed in correctly and the credit will be done the next month. I am not happy with that because I was never told my debit orders will change month to month. I need a solution to this even if it’s cancelling my contract, I am more than happy. I am fed up with this.