If you booked a "package holiday" then you get your money back regardless what the cruise company says or does. the money comes back from the tour operator. By law.
But what is a package holiday?
Its when there is a prearranged combination of ,say, flight and hotel (or cruise, or coach tour) that is presented for sale ,usually but not neccessarily, in a brochure.
For example, the big companies Panorama, first choice are offering packages.
if ,however, you just picked a cruise from the MDC brochure and picked a flight to join that cruise , and that agent bought them on your behalf then this is not a package as per the Act -and ,yes, you can lose your money.
I am guessing that your booking was the second thing, but do check in case it was advertised, presented and billed as a package.
its complicated and a rather fine line between "package" and booking items seperately but a careful study (of the adverts and brochure of the travel company, booking conditions, invoices) and a quick look at the Package Holiday Act could save you and other affected clients a lot of money.
Very briefly -and maybe not too accurately - did the travel company say "we can book you a cruise/hotel, tour with the company concerned and book you a flight"
or did it say "we have great fly-cruise/hotel/tour etc holidays".
Not, in law, the same thing.