MTN *****s again

MTN your service is so beyond shocking, I really don't know when you are going to get it right. You have sent me my business line invoices and instead of them being billed at R269 per line, you have billed me at R503 per line. When I query this with you I am told that this is a billing issue and don't worry, we will rectify it at the next billing. May I please give you a lesson in ethics and the legalities, 1) You may not debit a customer for more than what they have agreed to and signed for and 2) This goes against CPA. Stop *****ing money that I don't have to waste on your incompetence.