I had to take my sad child away from a place where he was having fun all because other parents can't…

I had to take my sad child away from a place where he was having fun all because other parents can't keep an eye on their children. He came to me so upset that this little girl pulled his hair and told him he wasn't allowed to play. And where is her mom? Sitting at a table on her phone and eating pizza. Please, let's teach our children about sharing and being nice! They were the only two kids in there and my son was afraid to play on anything because he thought he wasn't allowed.