There is only one correct response to someone like this, and note the utter absence of addressing HIS issue at all:
"Help! Help! You are assaulting me, and I am afraid for my safety. Get away from me, or I will call 911. I am recording your assault on me!"
Repeat over the top of anything they say. Do not let them get a word in.
Yes, it feels extreme, but a few facts:
- You do not have the option to clock the dude.
- Arguing with them won't work... That's what they want. By confronting you, they've already shown a confrontation and argument is a price they're willing to pay.
- Give them a reason to disengage and walk away. Getting caught up with the police in an assault charge will always do it. Your showing, out of the gate, your eager to take this much farther than they are, believe me.
Try to be nice and explain where they're wrong WON'T WORK. They already know. How many times do you think this jerk has tried this, and been corrected? They just want things their way, even when they know they have no right. They use aggression and intimidation to try to force what they want. They're narcissists.