Over-billed and no response

I have two billing queries which have not been responded to . <br> <br> I logged a call (Ref ***) on 17 December 2015 and explained the over billing. On the 28th of December, a useless idiot from your call centre called back and I had to explain all over again. After promising a response two working days later, I have not had a response for two months.<br> <br> On Inv *** I have also been charged for \Remaining Charges'\" of R501.89. I have no idea what these are.<br> <br> I also can not view my invoices or usage on your thoroughly **** website.<br> <br> This serves as notification that no further debit orders will be going off against my account until these issues are resolved to my satisfaction."