What is the best solution to my problem?

In October of last year, I got into a very small fender bender... I'm talking only $300 in damages from dents from license plate screws. It was just a tap... I bumped into her and we pulled over. I didn't have insurance.. BUT I was driving legally because I paid the uninsured motorist fee of $500. She got out the car and I provided her my contact info. I have no problem paying a debit I owe. I received a letter recently from a collection agency threatening to suspend my license because of nonpayment. Two things: I was willing to set up payment, but when they told me the amount I became worried. The total is about $1500 due to medical bills. They wont provide any details about the medical bills due to a "HIPPO"? law? Plus they told me that the medical bill wasn't added until several months later, I don't believe the medical charges are valid. So can they really suspend my license for nonpayment and how do I dispute the medical portion of the bill?