Tread and Miller

Two and a half weeks ago I returned shoes and they refunded me via card. I still haven't received the money yet. I have made multiple calls, send emails and phoned. At first they told me that I used another card after I told them that I only have one card. They then told me that my money is with my bank. Went and consulted my bank and they said that they don't have the money. Made contact again and had a conference call with my bank and the assistant whereas the informant at the bank made it clear that the bank account where they transfered the money to, doesn't exist at ABSA. Now all of the sudden I was informed that the money is in a FNB account, I don't even have a FNB account. How is this possible? How is this my problem? I just want my refund refunded to my bank account. All they tell me the whole time is that head office is not getting back to them. So over this!