I'm sorry about your experience there. It sounds terrible. I certainly wouldn't go back...ever.
Point of law: If you are served what you ordered and you eat the food, you are obligated to pay for it. Regarding bad service, you certainly can complain to management, and should. But you did that to no avail. So don't go back, and don't refer them to your friends.
Also....these people who are advising you about using devious measures to "get back" at the restaurant, really make me wonder. There's no way you can justify lying and making up a big stories for the health dept. or do any of the things suggested. Well outside of the bounds of honesty. It's actually childlike, if you think about it. The way school kids might react in the fourth grade.
Just don't go back. Relate your experiences to others. That restaurant will collapse with this kind of scrutiny and comment. Hopefully, that will be good enough satisfaction for you.
Onintwo