Most inventive, clever, sneaky, last minute cancel/NCNS/refusal/upselling/bait switch ever experienced?

They say you learn better from actual examples rather than from reading it from textbooks. Reality and practical usually wins out over theory. With threads/posts on cancellations, missed appt, etc, one can be really angry and hurt, either one or both sides. Anyone willing to post unique situations so all can learn and help to deter future situations? Seems like there has been some interesting NCNS and last min cancellations withing last couple weeks on the board.
The ones that never cease to amaze me (it has only happened to me twice ever) are the ones that walk in your door only to immediately say "I left my money in the car" and run (NOT walk!) to drive away!

Years ago, that happened to quite a few of the ladies not infrequently. I just don't get it.

One girl (she was young) had a client climb out the window.
The only time I've ever walked out on a session was with a BP girl back in my early hobby days. I showed up at her incall (apt) and when she opened the door it was very apparent that this was the girl in the BP ad but she was at least 6-8 older and 50 pounds heavier. Add the fact that she looked liked a used up SW and it didn't take me long to do an about face and get the hell out of there. I had to walk back down a flight of stairs to my truck and the whole time she is yelling obscenities at me telling me I didn't know how to get laid without paying for it. LOL