Unfortunately, kids these days know they 'hold all the cards'; if I'd have shouted something derogatory at an adult when I was their age, I'd have expected a thick ear or worse. If I'd have gone home and told my parents that someone had clipped me around the ear for being cheeky I'd have got another one from them!
These kids know that if anyone touches them in any way, shape or form, they report it and you end up in court! This is why there is no discipline in schools etc. Adults are too frightened of the potential consequences!
As much as you'd like to wipe the floor with these little scroats (probably as much as I would), it just ain't worth it!
You didn't over-react in my book, but just keep pedalling!