Delta Refundable Ticket Policy

Refunds for non-restricted refundable prices given by Delta Airlines can be requested up to 3 hours before the planned departure.
Up to two hours prior to the scheduled departure, Delta refundable main cabin fares are permissible for a last-minute cancellation.
According to the cancellation policy of Delta Airlines, any refundable fare combined with lodging, rental cars, or a combination of all three offers a refund on the flight fare only. The Delta refundable cancellation policy does not apply to hotel and rental vehicle refunds, which must be requested directly from the third-party seller.
Passengers may request a refund on a refundable Delta ticket in the event of a no-show, but they must pay a no-show penalty of $150 USD and a Delta cancellation fee of $200 USD before receiving the remaining fare value.

Check also : Allegiant Air refundable cancellation policy