Well, I would not be blaming the doctor...the insurance companies are awful to deal with and seeing it from the doctors' side, I say the insurance companies try to find a way not to pay and they make the doctors as well as patients jump through hoops to get paid. It's a messed up system. With insurance companies always making changes, I'm sure it's also difficult to stay on top of things.
You should call your insurance company and try to get it straightened out because it is your insurance company, not the doctor involved. They try to participate to be in-network with the insurance companies to benefit you, not them so much, as they get piled with rejections, paperwork, insurance problems, and more. It is the patients responsibility to verify your own benefits!
Sorry to hear about your problem, but I'm sure it can get rectified with some patience and polite phonecalls.
Best wishes for your health and happiness!!!