I paid $10000 for the FSD..
My 2c - Anyone could tell you that FSD isnt worth 10k right now. Standard AP is more than adequate for day to day driving, IMO. So I agree, I would be upset too, if I paid $10k for something that doesnt work well.
I am no-cult guy, but coming on a Tesla forum to ask about how to take legal action, not your best idea. A great idea is go to reddit. Reddit is the fastest and most reliable fact checker online - just preface everything with "prove me wrong" and you'll get answers...FAST!