Grocery store nightmare

Taking the girls to the grocery store drives me nuts! I'm sure it will get worse when they are a little older and can ask for everything, but right now it sucks. The moment we walk in they both start howling because they want to walk around. I always look forward to Zach coming along so if they get too out of hand he just takes them back to the car. Well yesterday we only stopped for a few items and the girls started throwing a tantrum. Zach grabbed them and put them in a new cart while I was standing in line to check out. All of a sudden all these people started gasping and pointing, I look over and see Kaitlyn laying on her back screaming her head off and who would of guessed, the crazy kid jumped out of the cart!!! From now on they will not be riding in the basket! She wasn't injured thank goodness, but I'm hoping it scared her enough not to attempt something like that again.