It sounds like it may be futile persuing it legally, but it doesnt mean it has to end there.
I would contact the local newspaper and perhaps write an article detailing your experience. Just be carefull how you word it, so that she can't claim defamation. Just state the facts and how her behaviour made you feel, no accusations.
Is there some kind of Better Business Bureau you could file a complaint to?
Hey, while you're at it, call a few local radio stations and tell your story, and ask if anyone else out there had had a bad experience with that groomer.
You just may be successfull in affecting her where it hurts [her pocket], and more important, save someone else from this nightmare of a woman.
Good Luck