Your experience is typical of this years changes I have seen across most cruise lines. I take 6-8 cruises a year across all major cruise lines. In the past it was simple to add or change the structure of a cruise reservation. Now the systems and promos are so convoluted, that, in most cases, you have to cancel your original reservation (hopefully getting the deposit refunded if it the right time frame), and then re-book the newer/better offer or add-on as a new reservation. The popularity of cruising has skyrocketed and ships are booking (in advance) like I have never seen before (especially the river cruises). Lately, I was receiving better offers for future cruises I had already booked. When I try to change to that better offer, the price of the cabin was substantially HIGHER thereby offsetting any benefit from the promo change.