When I was in the bar scene, I saw quite a few farangs get quite angry when they were rejected by a bar girl. I can't recall ever having been rejected myself, although that could be a case of selective memory, or setting the bar lower in terms of beauty.
No-one can MAKE a bar girl or P4P have sex with someone if they don't want to. I saw a couple of times where a persistent farang was ganged up on by Thais, female and male, in the vicinity.
If I had encountered rejection, no problem. Plenty of other fish in the sea.