Show up to court on the date listed, bring witnesses, and stick to the facts. Main point: you weren't arrested so there was no probable cause to believe any of this actually happened.
Your letter won't do the job, and in fact, will probably be ignored by the Judge as hearsay. Go to the hearing and tell your story. And if you can, bring your witnesses with you.
I hope you found my answer helpful. If you did, please click "helpful" and/or "best answer," because doing so helps my Avvo rating. Please also understand that answering this question doesn't make me your lawyer, and my answer is not even an "initial consultation" with me. In answering your question(s), I am merely giving you VERY GENERAL ADVICE based upon your VERY GENERAL QUESTION. If I indicated that you need to see a lawyer personally, then PLEASE DO SO. Good luck to you!