The following is speculation & supposition because, I wasn't there.
Whose fault was it that these 'teenagers' were in the position of having to seek refuge in the café? It wasn't theirs, the train had been cancelled because of Covid (yeah, right, sounds much better than the driver didn't turn up for his shift because of a massive hangover). Perhaps their parents had taught them don't hang around the stations there are pervs and deviants ready to take advantage go somewhere where there is a crowd so that you are safe, so off they trot to the café, having had a grand day out in Accrington the girls had spent up buying souvenirs of the place and hadn't foreseen the extra expense of buying a brew but never mind at least they will be safe.
If they don't know that particular café has problems with people hanging about (perhaps there is an epidemic of cancelled trains?) they may have been surprised by the waitresses attitude and taken it as a personal insult after all they were only seeking refuge. Maybe either or both parties could have handled the situation with a bit more care?
Maybe we should go back to 'Ladies only' waiting rooms on stations if the P.C. and equality brigade will allow?
As for the latest tech, most teenagers have the hand me downs from their parents and older siblings (had their 'phones been the latest tech the batteries are much more efficient and would have lasted the day) though I don't see anything wrong with any teenager having the latest tech if they or their parents can afford it.
As I have already said I wasn't there so I hope the waitress gets over her traumatic experience of dealing with teenagers and I hope the teenagers got home safely, I wonder, will they return for another adventure in our wonderfully hospitable little town?
Typical! teenagers invading our space and not buying drinks.