Damn, that sounds disappointing, almost a real-time Bait & Switch. Not something I have experienced here, or heard of others encountering there, but good to know. FWIW, Flora is definitely worth a visit, so I think your goal was a good one.
But about the situation you found yourself in, I've definitely been there, although not at AD. It's annoying showing up, thinking I had asked whether someone is busy....thinking they were not....and then they are. How much time passed between your call asking if Flora was available "now," and your arrival? At the Manhattan GFE spas like AD, MAGFE, NYAW, I've found that the best way to make sure me and the MMS are understanding each other is to name the time I want to come and the girl I want to see, and then repeat it to make sure.