Originally Posted by
Kacee
My experience is with UA, where they will give you both the fare difference and fixed cs comp based on the length of the flight. In determining fare difference, there is much play in the system. I've had success telling them what the differential should be, but the airline will generally default to day of departure fares, which of course is highly favorable from the carrier's perspective.
They certainly will, especially UA. My one and only D.O.T. claim was about exactly this. This was years ago (2010? 2011?), but it was a swap from an A320 to an A319 (back when the F cabins were different sizes on UA) and they claimed that the difference in fare was effectively $0. The D.O.T. disagreed, and I ended up with a credit card refund of around $600 and a CS gesture of $500.