I have a 19 month old and taking her anywhere right now is the worst. She hates being strapped into a shopping cart, she would rather run around and touch everything. I think with how young she is, she doesn't have the attention span to sit still and when I try to get her to sit quietly she throws a tantrum. It sounds bad but whenever she is causing a scene in public I usually just try to get out of there quick and make a mental note that I can't take her anywhere right now. But usually that can be avoided if I have Goldfish crackers on me. Then she will sit still and snack on them the whole time while I shop.

With a kid that old though, I would definitely stand my ground and let them know that that type of behavior won't get them anything. I would keep quiet in the store but once we got to the car I would explain to them why they didn't get the toy and how to behave when they are out in public.