Waiting for overpayment return

I have been in regular communication with Lindsay at expedient re a payment that my Medical Aid made to my dentist for an account which I had already paid in full. This therefore resulted in an overpayment which I have been trying to recover. Unfortunately I have been shoved from pillar to post by Xpedient, and I have been **** to by their staff. I have now been told by my dentist that the overpayment will only be returned to me at the end of December. This is totally unacceptable as the medical aid paid the overpayment amount on the 21st. November. It should therefore have been returned by the end of November at the latest. If I could give Expedient a score of zero I would.