I need my children's shot records!!!?

When my husband had insurance through his job, we took our children to a different doctor that is in North Carolina. My husband was laid off, but we really liked the pediatrician we were taking them to and we went a few times (maybe 3 times) after he was laid off. This caused us to have a balance with the Dr. of about 900 dollars. I don't have the money to pay the bill, my husband still hasn't found a new job. I don't have any family to borrow from, and I don't have good credit for a bank loan. Right now, I have no possible way to pay this 900 dollars. However, I do need my children's shot records to enroll them in kindergarten and 4th grade in the fall! The new doctor my kids are being seen by has requested the records from the other dr. in North Carolina (we live in southern Virginia) but they refuse to send them because we have an outstanding balance. I can't do anything about the money, but can they hold my children's records hostage like this just because of money??? How in the world do I get them?