Still waiting on refund

We have received the worst service ever from Cape union mart. My husband made a purchase there in June. The purchase went off twice, and since then we've been struggling with them to return the money. We went in store on 30 Oct to report the issue. They sent us to the bank to make sure it wasn't reversed or that the money is not somewhere in transit. We brought them the bank statements and they said they will ask head office investigate. We phoned the store manager every day the following week. Everyday she was either unavailable on a break, etc. And nobody else can assist. We phone there head office 3 times (4, 18 and 29 November. Each time we were promised that the area manager would get back to us or the store would get back to us, but nobody does. How do we resolve this?