Show them all your proof relating to the dispute including proof that they money was with drawn. I’d also call the CC company and inquire about the whereabouts of the money that was withdrawn. They should be able to see what happened to the money. If they sent a check and it was cashed, should be easy to show proof.

No reason for this to go to court. But crazy people gonna do crazy things.

But once it gets to a lawsuit, not worth fighting it anymore! Just pay it at that point. Your first attorney bill will be more than the disputed amount.