<human>: Give me the gist of the text in a nutshell

My parents were scheduled to fly out of a Canadian city into the US, and got through security without any problems. About an hour before their flight, they hit US Customs for preclearance, and they were taken for a random check because apparently my mother's fingerprints did not clear their system. They were whisked away to the customs area, where they were made to wait a for an hour because it was lunch time and nobody was there to work. Finally, they get checked out (which only took 3 or 4 minutes of someone looking through a computer), but as a result they've missed the flight, and are forced to shell out $300 each for a red-eye flight.
<bot>: My parents got screwed by US customs. Is there anything to do to get compensated? At the very least, is there anybody we can complain to about this?