Right, deep breath, never posted in AIBU so be constructive please!
I have just come back from doing my weekly supermarket shop. As I walked in to the supermarket I noticed a young child sat in a car seat in a car on his own. Not sure how old but certainly below 4. The child was crying. I walked in to the entrance of the supermarket and decided to look back to check if someone had returned to the car, but they hadn't, so I stood for a while longer. I was concerned about the child so in the end spoke to the customer service desk just in side and said I was concerned about the child in the car alone. The customer services lady walked over to the car, the child was still crying, another member of public expressed her concern. The customer services lady then put a call out over the tannoy for them to return to the car. A few minutes later a lady appeared and explained that she could not bring the child in as he "would be a nightmare" and she was doing her shopping as quickly as she could. I said that she shouldn't leave a child in the car alone for that long, to which she responded that she was going to sort her child out and was then going to continue doing her shopping. She annoyed me at this point because it seemed so normal just to leave him in the car, and that he was crying. I said that if she did return to do her shopping leaving her child in the car that I would call the police (probably a little over top of me I know).
Now don't get me wrong, I have 3 children and do leave them in the car when I nip in to a shop, but it is always where I can see the car and literally for a few minutes. Today we were at a main supermarket and she was doing her main shop, whilst small child is in the car. If she had returned looking really stressed I might have had some sympathy and thought she was struggling, but she was impeccably dressed and made up, and talked very calmly. I feel rubbish now for interfering, it is not something I normally do, so was I BU for interfering?