Disgusting service

I took upgraded my contract with a black Friday data deal that MTN was offering. The contract was for R299.00, i was debited R2000. When i queried this they said it's a pro rata amount which didn't make sense at all and was told my refund is being processed. I called the call center again in Jan 2021 and they said its still being processed. In Feb i went in store to get help and was told they unable to assist only the call center will be able to help me. I called again in March and they said its been escalated but still no refund. I now have two reference numbers and called the call center on numerous occasions but still have not received my refund almost 5 months later. I am highly frustrated and there's no one that can help as i can not speak to a manager because their call center agents are working from home. Disgusting service.