Most Helpful Guy
Had something similar happen to me. Back in undergrad I was in the fz with my best friend (I was a dumbass, regret the whole thing but anyway lesson learned). She had a boyfriend since we first me. Once she graduated (year older) we sort of lost touch and didn't hang out as much. Had no clue if she was single etc, since she like never ever talked about her boyfriend.
Anyway I couldn't take it anymore so one day I called her up and asked her out on a date. Her response was she would love to go, but couldn't because she was in a relationship. She then said if she was single she would have definitely said yes. I took that as a sign of interest obviously and thought that hey maybe she has had feelings for me all these years. So I told her that if she's ever single to let me know and she said not to worry, she definitely will and even sounded happy about it. Half a year later I found out that she ended up breaking up with her boyfriend a of months after I asked her out, yet she never let me know... hmmm. Obviously, I was pretty hurt and mad for being strung along like that. She didn't have to say all that other stuff that gave me false hope.
I never got any revenge, nor want any. She probably said that stuff because she was on the spot and wanted to be nice, I get it, not happy about it, but I get it and accept it. My revenge I guess would be that I've moved on to bigger and better things.
Most Helpful Girl
There is no point in trying to get revenge from someone who doesn't like you. They dont care about you. Whatever you do will just make you look more hung up and obsessed with your ex. So rather to let go and move on instead of being the girl who can't get over a guy who treats her like crap.