Hi Pat:
This is from my TA friend:
If the airline cancels, demand a refund, not travel credit. They are required to refund. Ask for a supervisor, that should do it. If not, threaten to file a claim with the DOT (dept of transportation). They will refund.
And if you booked thru Expedia etc, you are on your own. They will not do it for you. Have the ticket number available.
Best of luck,
Ellen