Refund from VW after a double payment from the client and Insurance

I booked my car for a windscreen repair on the 23rd November at VW Bethlehem. After 3pm Insurance told them they will send POP the following day, so I had to pay because they would not release the car if it was not paid for. We then agreed that they will refund me after receiving money from my insurer. Indeed payment was made on the 24th and they said they start the process to refund me. It’s been two weeks now and I still haven’t received my money. When I call they tell me that they do not deal with payments and the issue is being dealt with by their VW headquarters in Newcastle. They have my money and the insurance money now they do not want to pay me back.