If OP books the ticket on a DL channel "right now" as he says, he has until midnight tomorrow to cancel for a full refund to his original form of payment, e.g. credit card.

"Cancellation request must be made by midnight of the day after the eTicket is purchased or midnight of the departure date of the first flight, whichever comes first. Cancellation request must be made before travel commences for the first flight. Available only for eTickets purchased at the time of reservation through Delta ticket offices and airport ticket counters, Reservation Sales, or at delta.com."