Data Billing Errors STILL not fixed after 8 months

Ever since we renewed our cellphone contracts in May 2015 (2 contracts for our Company) we have been billed for data (at out of bundle rates) for data that we actually PAY for every month as 1GB recurring data. The MTN store in Vincent Park Centre confirmed that it is a technical error and the data has not been \loaded"and they will fix the problem. Our one number seems to have been fixed now (not charged for data anymore) but the other number is still being charged for data (out of bundle) although we have been paying for 1GB recurring data every month. The number that has been \""fixed\"" though is now being charged at a higher rate (R140.35 for 1GB) and the number that has NOT been fixed is being charged at R114.65 for 1GB but the data is not actually \""LOADED\"". No joy from the Call Centre and numerous emails with copies of all invoices & correspondence to the MTN Store in Vincent Park Centre (Mr. Eugene Barnes). MTN now owes us thousands of Rands in billing errors and not refunding us and have still not FIXED the problem! How long is this going to continue???? We demand these errors to be fixed immediately and to be refunded for YOUR mistakes!"""