Try directly contacting the airline, rental company, hotel, etc., if you've redeem your rewards for travel-related items. They may be able to assist with rebooking or refunding what was cancelled.
If the merchant issues a refund, you may want to clarify if it applies to the original payment method, or if they're offering a credit to use towards a future purchase with them.
For more details or any questions, contact our Rewards Center at 888-229-8864. We accept relay calls.