I recently rescheduled an Air Deccan flight and was to receive a refund because of the difference in the fares. I expected another delay, but found that my Visa account was credited with the refund the very next day.
I also had a nice trip with them on this flight, and so have booked another trip.
Staying on the subject of air fares, it's amazing how much variance there is between the fares across different airlines for a given route. Forget different airlines; the price varies significantly even for the same airline for two different flights on the same day. For example, a ticket from Chennai to Mumbai costs Rs 1000 more if you opt for the evening flight instead of the morning one. Welcome to the world of we'll-charge-you-as-much-as-we-can-get-away-with, a.k.a. demand and supply, I guess.