Question Over Cruise Liner Law Base

I heard from a pal who was still getting over a recent ‘discussion’ with a chap who purported to be the customer service manager of a big cruise line.   This chum has been booked on a cruise with her family, to start this autumn and was greatly looking forward to it.  All the way through since paying her deposit upon booking there have been various optional items available to buy – drinks packages etc.   They were a set price and hadn’t altered from day 1.  Strangely though as soon as they all paid their final balances, these optional items became ‘out of stock’ and were replaced by the same thing but called another name and at a much hiked price.    She was surprised and called into question the legality of this – to be told they could do as they liked, they operated under their own country’s laws.  The cruise line parent company is based in the States.    His conflict resolution skills were zero and he was as obnoxious as anyone could imagine.  Not what you expect from a major company in the UK.   The interesting question arises of whether they are covered by different laws over here as they sold the cruise out of their Southampton UK base.     We shall see what occurs . . .