Bumped into an "upgrade"

Back in May, I booked a Galapagos Island cruise on the yacht, Fragata, which was scheduled to leave later this month. Today, I received an email with the following information:

Due to an unintentional error on behalf of the operator of the Fragata, they have upgraded you to the Luxury class motor yacht, Beluga! For more information on this yacht, feel free to go to http://www.enchantedexpeditions.com/yachts_beluga.htm

While the "new" yacht is probably nicer than the Fragata (it costs more than 2X that of the Fragata), I didn't pick the cruise based on the yacht. I picked it based on the itinerary. With the Fragata, I would visit Genovesa, Santa Fe, and South Plazas islands. The Beluga does not go to any of these three islands! Instead, it goes to Fernandina and a couple of places on Isabela islands.

I'm sure these are very nice, but I spent weeks researching the different islands and which animals I wanted to see. I was willing to pass on seeing the flightless cormorant (on Isabela) to see the red footed boobies, red-billed tropic birds, and short eared owls on Genovesa. (I can see the latter two birds on some of the islands that remain the same for both itineraries, but they aren't as "easy" to find on those islands as the ones I am giving up) Both Santa Fe and South Plazas are excellent places to see land iguanas. I'm not sure I will see them on Isabela.

While I'm sure that I will have a great time once I'm there, I can't help but feel extremely disappointed that the trip I invested a great deal of thought into planning (and paid for months ago) was drastically changed so close to my departure!