3 and a half months, Dr still not fully paid!!!

After precisely following procedures and making countless phone calls and writing endless emails, my orthopaedic surgeon's account has not been paid in full. Its been 3 and a half months and this issue is still not sorted out. I've explained to them that the doctor's office has incorrectly dated the invoices sent to the medical aid, and then I let them know, so they sent their correctly dated invoices through but it's still not settled. ***. I don't even know what to to anymore, between being harassed by the doctor's bookkeeper for the money and trying to explain to the useless call centre folks what the f#@??%&amp