I went to Wendy's few years ago and ordered a cheeseburger plain. Nothing but bun, cheese, burger.

I drove home and opened up my wrapper and found every single possible topping in the sandwich, tomatos, onions, mustard, mayo, etc. But it was missing two things, the burger and the cheese. I thought maybe I got a veggie burger but it also had bacon on it.

I called the store, coupon was sent in mail. I didnt flip out, make a scene, make a big deal about it. As said before mistakes happen.
But I learned to check every single time I go to the drive thru and it only takes me about 10 seconds.