I canceled an F ticket (the fare rules said refundable, and I didn't notice a cancellation fee -- we shall see), then filled out the on-line refund forum. Nine days later, I got an e-mail acknowledging the submission and saying that they would process the refund -- with the funds returning to the card in another 21 days (plus any extra time that the bank takes).

It sounds from others' experiences here that this is a conservative estimate, but, still, this is completely outrageous. It should be instantaneous -- it certainly is when they take your money.