Someone just called back. I suggested they see if there are multiple records for the doctor, with different phone numbers or tax IDs. They are still looking into it, but the problem may have to do with the tax ID - whether the tax ID on the bill (which was submitted electronically) is the same one that was contracted with them. Or if the bill used the individual provider ID or his group's ID.
I wouldn't have been able to help if I hadn't worked with the provider file at MetLife (tax IDs! doctors being listed individually or by their medical group!). But what do people do who didn't work in group insurance claim admin for 17 years?
On another front, good news from Amazon. I never received an Incredible String Band CD ordered from a marketplace vendor during the summer. The vendor sent a nice E-mail saying they were not able to get it from their supplier, but then I never received a refund, despite writing to the vendor 3 times with no answer. I finally initiated a formal complaint and BOOM the refund was applied within hours.
So now I have that refund plus 3 gift certificates to play with on Amazon.
Edit: I ordered a bunch of stuff, and just went down to get the mail. There was another Amazon gift certificate (I have a credit card that accumulates points good for Amazon certificates). Darn, too late! I'll do another order soon.