Lesson for the day: That business establishments shouldn't take customer service for granted. We hate being passed around like a basketball.
I am not a member of fitness first. But even so people from fitness first should be prepared for these kinds of things. Its part of business. Your reactions for me seems to justify your customer service blunders.
Hitting on former customers will not do you any good. It just muddles everything. More people will have 2nd thoughts going to you. So your reactions are defeating yourself.