I took DS1 (12) and DS2 (11) to get their school shoes yesterday. We got on the bus and downstairs was busy so went to sit upstairs. We sit at the very back, with my partner.
Two stops later there was a bang on the side of the bus as it pulled up to the stop. I thought someone had been hit as there was shouting. Turns out this young girl had ran at the bus and hit the doors. She was about 12/13 and with a friend of about 14/15 and a boy of the same age.
A few minutes later they come upstairs and are visibly dissapointed that we are at the back.
This girl is SO loud and mouthy. She dramatically runs up the aisle and plonks her self down on the last seat before ours.
She is shouting about how she had stormed out after hitting her dad 
and screaming at her friend about 'not being allowed to fucking talk!' She was awful. Everyone on the bus were exchanging glances.
Now my sons don't go places without me. They are very polite and reserved.
My DS was sat behind her, facing my gf as the seats at the back face each other.
Whilst she is hollering and shouting my DS and GF are talking about something completely unrelated and DS laughs.
Next thing I know this girl gets up, comes round the seat and leans down into DS and starts shouting "what the fuck are you laighing about?? You know nothing about my life. Who the fuck do you think you are?"
I leaned forwards and put my hand against her shoulder (not pushing her just creating a barrier) and told her to back off and leave him alone.
She then turns on me. She put her face literally ab INCH away from mine and started the same shit with me. My gf stood up and told her to basically piss off and she had brass balls and carried on shouting.
She storms off and sits halfway down the bus and starts shouting about 'people listening into her private conversations'
So I say 'no body wanted to listen to your drama love but you were screaming loud enough for the whole bus to hear and he wasn't laughing at you!"
The bus driver came up and made them go downstairs (the older girl was just laughing the whole time but the older boy did try to control the littler one) He didn't even kick them off the bus!
DS said he was ok but he looked a little shaken and they did say on the way back he hoped she wasn't on the bus home.
Should I have done more? Complained to the driver? Called 101? She was so aggressive and out of order.