I'm ticketed round trip AUS-IAH-MCO on some kind of advance purchase fare of $229. I thought that was pretty decent. I see now that the equivalent fare is more than a hundred dollars less at $119!

On UA and a couple of other carriers I know that if everything is right (same fare basis still available and compliance with advance purchase dates, and so on) I could get a voucher for the difference which would be good on future travel.

Does CO do anything like this? What's the best way to approach them if they have this kind of policy? Thanks for your help.