First off learn the terms. The fact that you may be innocent doesn't make you falsely charged. Charging only takes probable cause, not proof beyond a reasonable doubt.

Believe me you're not going to be hung over the fact that the license was oriented one way or the other. You're going to be convicted because DESPITE what you think you recall, they sent a person with a license that indicated they were not 21 and you served them. All the rest of your arguments above means nothing.

You have been charged with a CRIME. You can go to JAIL for up to 6 months over this. The fine will be $100 plus costs. I would recommend you consult a lawyer. Court fees are the LEAST of your worries.