instead of a refund, they give you MCO (Miscellaneous Charge Orders) which are credits you can use for future flights. MCO's can only be redeemed manually (via a travel agent, a city ticket office, at the airport, etc.) and not online yet.

I believe they are now charging $25 for each reissue (when the fare drops), so even though you are saving money, it'll still cost you $50.