Gotta agree that the OP shouldn't have directed her comment at the check-in agent. CO is a huge corporation, and a hassled agent isn't, realistically, going to make a mental note of the complaint and forward it to the proper party in CO's IT department. OTOH the agent's reaction was beyond uncalled for -- it is completely unacceptable to suggest that a customer "take their business elsewhere" after they nicely offer constructive criticism -- and in my personal opinion he should be fired for it.