Southwest Airlines states that only some flight reservations are refundable, regardless of the method of purchase. If a flight is refundable, funds are returned to the original credit card on which the flight was purchased.
For refundable ticketless reservations, a customer can call Southwest Airlines to request a refund at 1-800-435-9792. For all other reservations, a request must be submitted in writing to Southwest Airlines, Refunds Department, P.O. Box 36649, Dallas, Texas, 75235-1649. Refundable tickets with no other restrictions can be applied to future flights if they are not used for the original flight. A customer can cancel a reservation online by submitting a request via the Cancel Air Reservation portion of the Southwest Airlines website.