CO apparently has a policy of a $250 elect cert for downgraded passengers, even if the upgrade was by EUA. Without even asking, I was handed a $200 cert by the GA before this was policy when I showed up for an EWR-SFO flight that I had been upgraded on and there was a change of equipment. So I believe you are due that. You also should have your miles redeposited.

More important, I think that Scott or someone else should investigate this to determine whether it was GA shenanigans like seating a friend or non-rev in your FC seat, or whether it was a late arriving connecting passenger. There should be a record of some sort regarding what happened. If there is a reasonable reason for what happened, I would hope it could be made public on this forum, if not, the GA should be disiplined,or reprimanded, or educated, appropriately. But we should be given some type of explanation. Added note: I for one think firing is overly harsh unless the employee in question has a lot of black marks already. I'm certain that CO has plenty of options ranging from re-education if it was an honest mistake by a new employee to warnings and on up.