Eileen,
That's a kick in the teeth. (pardon the pun.)
You may want to explore this avenue. In Canada, I'm not sure if the U.S. or for that matter individual States are the same, dental and medical insurers have what is called an, "Alternate Benefits Clause". What this means that if a specific procedure is not covered that they will provide benefit if a lesser procedure could have been performed. Example: An Implant is needed to replace a missing tooth. The patient's plan does not cover implants but would cover a fixed bridge which is a less costly procedure. The insurance provider in this example would provide coverage for the implant but, only up to the dollar amount that they would have paid if a fixed bridge (less expensive treatment) was being done. I'm not sure if this applies but it would be worth investigating.
Talk to the office that provided the service to see if they can help you.
Cheers,
Mike