The 24-hour risk-free flight cancellation policy of Delta Airlines applies to all tickets purchased directly from the carrier. You have 24 hours to cancel any flight reservation made in accordance with this policy, regardless of your fare class.
Exceptions to the 24-hour policy on cancellations
The following are exempt from Delta 24-hour cancellation policy:
purchased tickets through a travel agency
physical tickets
Reissued tickets for portions of flights
You must speak with Delta Reservations if you want to cancel a SkyMiles Award ticket.
Check also : Allegiant Air 24 hour cancellation policy