Bad service and ******

Last month I fight with them about my account, they debit the amount of my statement that I already paid for example 3 days ago. I was really pistoff about is because they told me it is the amount of Call I made and the data I used but I never did. So then this month again my account will be debited for R640 again. This time it is a rejected payment fee and monthly fee + my billing amount ****ing so annoying. Please help me don't know what to do any more do that that money to pay every month..