I'd like to know what others think should be the right terms.
Initially, I thought I could go either way on this and use the terms interchangeably. However, with a little more research, I have come to the conclusion that while
neither term is ideal, rebook is
closer to being correct. It also has the distinction of being a real word, as opposed to retail jargon.
Rebook - The "to book again" definition may be somewhat ambiguous here. She certainly isn't booking the
same cruise as her first cruise again. It is a different date, location, and ship. However, she is essentially having
DCL staff cancel her reservation (an agreement between her and DCL for a cruise at a particular price) and then buying it back at a lower price. So it was booked, canceled and then booked again.
Certainly the second definition can be applied in this case. After all, the booking in question is being changed. She bought the cruise at one price and is changing her reservation (though not the date or room number) to get a better price.
http://www.thefreedictionary.com/rebook
Reshop - This is retail jargon for returning misplaced or returned merchandise to its correct location. For example, I see a pack of gum that seems like a good deal. At the register, I see an even better deal, so I (inconsiderately) put the original pack of gum down on the counter and select the one that is a better deal. This leaves the "reshopping" of the original pack of gum to an employee of the store who will return the gum to its correct location.
In this situation, she is
not leaving her stateroom behind to be "reshopped" to the "shelves" (or should I say "decks") of available staterooms that future guests will be choosing from. It would be more like me taking the original pack of gum to the service desk and returning it, then buying the same pack of gum with a coupon.
http://www.doubletongued.org/index.php/dictionary/reshop/
That said, I think the term "renegotiate" is most applicable in this scenario
http://www.thefreedictionary.com/renegotiate