CONSTANT NEGLIGENCE IN BILLING

Since June this year, Multichoice has been billing me incorrectly as I have had to switch from being a staff member of the wider Naspers group on their system to a normal paying customer. I have literally called in more than twice a month since June, spoken to multiple people, and each and every one of them have given me different reasons for the over billing (which happened for June month) , the billing that was not supposed to take place (for July) and the lack of reversal that was supposed take place as per my last call on the 26th Aug. Come September, they have billed me yet again without the reversal that was supposed to have happened the previous month, and without taking to consideration the over billing for June. I am at my wits end right now. I asked the last person I spoke to (Nonmiswa, I even have the ref number for the calls) what to do if they messed up yet again and all she told me was to email customer support. I don't understand how such a large company gets just the basics of billing so wrong and seems so uninterested in resolving customer complaints