OP I'm with you 100% - I live in an allegedly affluent town on the Sourh Coast and every other day our local rag carries stories about teenage stabbings and the re-routing of buses due to teenage misbehaviour and intimidation.
I'm in my 50s, recently widowed so feel pretty brutal about alot if things and have no fucks left to give.
I have faced off teenagers three times in the last six months.
On the way to my DPs grave I verbally laid into a teen boy attacking a bus shelter with a lump of wood. His female companion went nose to nose with me so I just brought on the crazy and threatened to call the police. She was bigger than me but I didn't care. They backed down and I did report them but they skeddadled so it probably came to nothing.
I was in my shop (niche, Goth, weird) and three young gentleman, one wearing a mask went past the window - I glanced at them out of reflex - one of them locked eyes with me and squirted his drink over window and the table and chairs I have outside for customers as it's a small shop and sometimes people sit and wait for actual shoppers - not sure who was more shocked when I ran screaming through the door and gave them a piece of my mind - me, the little darlings or the two friends who were visiting at the time. I got some verbal back but they went off.
Third occasion I was still in the shop after hours doing some admin and had my back to the window. I jumped a mile when someone banged the window so hard I thought it was coming in. It was the same trio so rinse and repeat - ran out and screamed like a banshee at them.
Yesterday I watched a child of four or five very deliberately spit in the eye of one of the skull ornaments I have either side of the door and then run off. I went out to see if I could have a word with the parents- obviously am not going Terminator on a small child - but the family had crossed the road and I think the parents were oblivious so that one I left....
My adult son is worried that I will get into trouble at some point but I'm damned if I'm going to let these kids attack my property and put my business at risk.
I have dealt with a lot of troubled teens as my sons were growing up, and will help, support and counsel if I can, but I will not tolerate mindless thuggery.
In a situation such as yours, you did nothing wrong and handled it well. But it's not fair that you were put in that position, and the authorities should be tackling anti-social behaviour in public places much more firmly.
I'm used to being laughed at and insulted due to being a lifestyle Goth, so have a pretty thick skin and accept I somewhat "ask for it" by being a bit out there.
But there are limits. And the intimidation of people with kids by other kids in situations such as yours makes my blood boil.
I'm sorry you had that experience.