Maybe you should try calling? But I guess some states MIGHT not have them. But they also could be called something different. OR if you live in the sticks I can see how you might not have one.
Not trying to start a seatbelt rant here but if I don't wanna wear it and I am the only person in my car I don't see the issue. I don't need you or the police telling me I HAVE to wear a seat belt. You will say "If you don't wear it you are stupid" To that all I have to say is this: If you are in a hospital you can refuse any life saving devices you want and it's not against the law. I also don't see people getting fines for jumping out of airplanes or doing other stuff that is not exactly "Safe". If you say you could hurt other people by not wearing a seat belt, show me the stats of projectile humans in car accidents causing fatal injuries to others.
If I were you I would call and see about a hearing officer or something along those lines. If they don't know what you are talking about or can't help you then take it to court without a lawyer. You might have to pay court costs if you lose though.