The ADA, while it has its benefits, it also has its pitfalls. I'm sorry that you were refused service but, I really wouldn't want someone's dog sitting next to my table while I ate unless the dog provided completely necessary service to its owner. So many people have service dogs now for a multitude of reasons. I know of two personally that have them because they are permanently disabled military vets. Neither of the two were disabled in anything to do with the military. Both were injured as acts of off-duty bad decisions but, they were issued service dogs as a result.
I don't know your personal situation so, I won't dare speculate as to your dog's function in your life. Best wishes.
Here's a link to some of the pitfalls of the ADA that I mentioned earlier...
http://www.facesoflawsuitabuse.org/2...ches-too-high/