I can't seem to get a straightforward answer to this question either in the terms&conditions or from the airline, so I'd like to know what your experiences are.

my flight with the regional *A partner last friday was delayed by 4 hours. the delay was announced almost three hours before the scheduled departure. I called the airline's airport counter where they confirmed the delay and that in this case it's best i stay home and arrive at the airport then (it was in the middle of the night). i arrived at the airport one hour before the flight to find out that check in was closed and the airline sold my seat (together with the seats of two other passengers in the same situation) to stand-by passengers. everyone else but the three of us was in transfer, so of course they were at the airport on time. after a lot of persistence on our part, the airline got us on the plane but the representative kept repeating that in case like this, we were supposed to be treated as no show and denied any rights whatsoever, since we were supposed to come to the airport at the scheduled time (and wait there). as the flight was delayed from midnight to four AM, that sounds just insane. was the representative leading us on or could they really deny us boarding and compensation? i'll be glad for any input. the t&a state only that check-in "closes 30 mins before departure".