Urgent-Please help-Fraud use of national park annual pass in yellowstone

[NO.1WAYTOGO]

What is the name of your state (only U.S. law)?
I live in utah. A week ago, I drove a 15 passenger van to yellowstone with 8 friends in it. I showed the annual pass to the cashier, but she said I have to pay 125$. I thought as I have the annual pass, why do i have to pay extra money? But she insisted I should pay it and eventually I gave one credit card to her. However, she didn't let us go immediately, but called park ranger.
The ranger gave me a Mandatory appearance viloation notice, charging of fraud use of annual pass, failing to pay fee. By the way, she did charge us the 125$.
What should I do with this? If the charging was confirmed,is the fraud use a crime? I didn't know what is the difference between commercial and non-commercial. I don't want to go to WY to attend the court as it is a long trip .
Thanks a lot for any advices.

 

[CdwJava]

Was the pass you had for your family? Were you using a family pass to try and get a commercial tour into the park?

What code section have you been cited for violating?

 

[Indiana Filer]

What sort of pass was it? Was it the one you purchase for $80 annually?

You can use the Annual NPS pass for non-relatives.

About your Annual Pass (Access pass for the disabled or seniors is also valid for pass owner and 3 accompanying adults.)

* Valid for one full year from month of purchase (through last day of that month).
* Allows pass owner and accompanying passengers in a single, private, non-commercial vehicle to enter Federally operated recreation sites across the country.
* Covers the pass owner and three (3) accompanying adults age 16 and older at sites where per person entrance fees are charged. No entry fee charged for children 15 and under.

I'll bet the problem was that you were in a commercial vehicle. (Just assuming.) What sort of 15 passenger van was it? Was it one registered to a commercial business? Rental?