Todays butt head customer

Guy and his wife and 3 kids come in, the oldest child is a little girl 6 or7. The woman asks the waitress is your Chili spicy? My daughter wants Chili. The waitress says yes indeed it is spicy. The woman says ok, give us a cup with cheese and onions. I'm sitting at the computer thinking, spicy Chili with raw onions and cheese for a 6-7 yr. old kid??? The waitress brings it, the kid takes a bite, says it's too spicy, the woman says she so sorry but you'll have to take it back, I say sorry, you were told, it was spicy, I'll take it back but you will be charged half price. This doesn't go over with hubby, and he starts bitching, I told him that were not some chain that can be played like that. I got the old we'll never be back line. they got my old line good, and tell your friends, if you got any, to stay away. I will not be abused by the public, I don't care if he writes 1000 bogus negative reviews on Yelp! Your reaction?
PS. The Chili has a kick, but in almost  11 years, never had any sent back, for it's heat.