Well we just have to except it we can't make everyone happy when we cook i found that out first had.

You have to wonder if everyone liked it but the ones paying the bill, then maybe they just wanted a free meal.
You can't please everyone, so don't let it get ya down.
This is a ploy used by many a cheapskate when dealing with Catering folks. Because so many of us did and do it without a license folks like to take advantage of it. They know we will be reluctant to take them to court for fear of getting into more problems due to the license. I always demanded a 50% deposit up front so I could at least cover my food costs. Sorry this happened to ya.
Good luck with the next one