I don't see anything actually dangerous or illegal here, just unpleasant and unprofessional. So reporting them to anybody I'm not sure will help much.
I'd walk away and leave them to it - go fly with somebody who cares both about good manners and professionalism. If the place was that quiet, then the odds are everybody else has already done so - market pressures will then either make them buck-up or close down.
Having said that, talking along the lines of "you blithering idiot why did you do that" is quite common amongst aviation professionals and I shouldn't let that in itself trouble you. Undesirable though this attitude may be, most full-timers would probably have simply carried on through that sort of feedback - there is much fault in not recognising you as a newly qualified pilot and treating you accordingly.
G