VA admitted they made a mistake and still have not fixed it after almost 2 months

Virgin Active double debited my accounts - I was told it would be an easy procedure to get this undone and have them pay me back. It has now been almost two months, I have called in over 10 times, spoken to more than 8 consultants and had my case escalated to a Team Leader and they still have not fixed the issue. I have also been very patient and never raised my voice with any of their consultants but this really is the worst service from any company I have ever received in my life.