It is true that a few of the airlines do NOT offer a 24 hour refund policy, or a 24 hour hold. They stick to the fare rules of the ticket purchased right after payment has been made. An alternative to do is to purchase these tickets through online travel agencies (Expedia, Travelocity, etc) as they use Global Distribution Systems where payment is not made until the following business day (especially for US based sites). Tickets are simply voided (just like how you request to void a product you are about to purchase from a supermarket) and the fare amount charged, which is basically an authourization or floating amount on the card, automatically falls off. Ticket void requests lasts until 11:59pm the following business day in US-based agencies while in Canada and other countries, it lasts until before midnight the same day the purchase has been made.