My experience is flight cancelations/delays will get refunded.

Christmas 2013/new years 2014 I went through travel hell with Southwest canceling my flight due to weather. I had to book on Delta a return flight.

Southwest refunded me but part of the refund took longer in split dispersements because I had used past credits in the booking of the flight then paying cash to pay the fare. Th3 cash payment was refunded quickly. The transferred credit took a few weeks (partly because they had a back log with all the flight cancelations due to the cold/snow storm affecting the great lakes and Midwest over a week or so.