I would never want to travel on a school service, commercial or not,find it very odd that you threatened to report the driver over it
Perhaps I've just been lucky but when I have used services largely used by school pupils the experience has been ok:
Shavington School, Cheshire - behaviour impeccable
Plockton - Kyle of Lochalsh - lively but perfectly acceptable
Liverpool area - irritated by the dropping of litter but not rowdy