System error costing R 8000 and no refund after 2 weeks

Several months ago, my contract was due for an upgrade. I first had to move my number into my name following my divorce and then proceeded with the upgrade. The person who assisted me then opened a separate contract without upgrading my existing number. It took 4 months to resolve this, with MTN double debiting me every month. Eventually it was rectified and the new contract was moved onto my old number and I was refunded. On the 1st of November, MTN then deducted R 8500 from my account - my invoice was for R690.42. When I followed up, I was advised that it was a system error and that I had been charged for an early contract termination. I was advised that it would take 72 hours to resolve. I contacted them again on 10 November. 5 people and 35 minutes later, my call was dropped with no resolution. I contacted them again on 13 November to follow up. I was advised that they were busy with the matter and received an sms to say that the matter had been escalated. This morning, I followed up again but was told that the call from yesterday had not even been reflected on the system. It is 2 weeks after they took my money. I have had to borrow money this month to pay my rent because of this. And I cannot get any resolutions from anybody. It is totally unacceptable.