That is absurd. The person in box 31 is not the one who gets paid. The billing provider in box 33 is who all insurances use for payment. There has to be an issue with the provider file. I would call back and get a different person. Explain the situation and see what they say. If they give you the same answer, which I doubt they will, tell them that you need to speak to someone in provider enrollment. There are several situations that I can think of where you would never pay the person in box 31.