Have you been driving since you were 16? I got my license at 16. I have a friend the same age who did not get her license until she was 18 and she pays higher rates. She pays more becase she has not been driving for as many years.
But, as Forums Nazi pointed out, there are so many factors that determine your premuim. Even your credit score can have an affect on what you pay. I would just keeping trying.
When I got mine, the lady on the phone had to get a senior underwriter to review my policy because of the original value of the car. I was worried at first, but they eventually approved me.
-Mike