Honestly, I can't believe you wrote this letter. You must know that there are plenty of people who do abandon those kids' carts in the parking lot. Parents with little kids don't want to leave their kid unattended in the car, so they just leave the cart wherever they are.

I don't find any problem at all with the store employee wanting to get the cart from you when you were done.

I just can't imagine someone having a complaint over this store employee doing what she did. The mind, it is boggled.