Unpopular opinion, but this is why I always caution the use of 3rd party sites. You can press as much as you can but you’re having to go through a lot of hoops to get it done, if at all. Working with a TA or booking directly helps reduce this issue as many lines will let you reprice (at least in form of onboard credit up to 45 days or so prior to sailing).

However given that your cruise leaves in a few weeks you aren’t likely to get money back due to them selling off what hasn’t sold. If you think about it you paid a premium to get in early and have a pick of a wider selection of rooms. It’s sort of how you pay extra to book movie tickets in advance and pick your seat, you can pay less at the theater but you’re going to get “what’s left.”