I haven’t had to deal with it yet, but I expect to just not talk to anybody who tells me the proper pronouns to use.
As someone at Paco Enterprises blog wrote, try saying, “Lighten up buddy.” if it’s a guy or, my longtime choice, “Listen honey.”
You probably won’t have to say anything after that as it should elicit a reasoned, intelligent, frothing insanity.
You’ll get a chuckle while not having to resort to profanity. NTTAWWT.