I went to a walk-in and they denied my insurance, will not take, and UPS denied it was a work injury so they would not cover it. That was one of the UPS approved doctors. Is that what you are saying?
First thing Monday you need to go right over your SUP. Call his boss or your HR rep and start to get results. You might also want to contact a Workman comp attorney and see what your options are. They will tell you your right and what you need to do and it isn't going to cost you anything for a consultation. You could also call your state workman comp office and file a complaint.