OK - IF there are any problems on board - and there might be small inconveniences you want fixed - call the Pursers desk (the number is printed on the phone in your cabin) and talk to someone there - GET THEIR NAME!! This is a big mistake many people do. I called and spoke with someone regarding the A/C being out in our cabin (very small amount of air coming out). My neighbors in the next cabin called too. I asked for the name of the person I talked too and when I called back, when nothing happened, I said "I spoke to so and so and they said...." This got results quick. My neighbors called but didn't get anyone's name and the Purser's desk said they had no record of them calling. SO GET SOMEONE"S NAME!
Everyone was very nice but it was a problem with all the back cabins (along the back on the ship) that cruise and there wasn't much they could do or would do. It honestly wasn't bad because we were in Hawaii and it was max of 80 degrees out and then we headed to Vancover where it was COLD! We weren't ever in our cabin during the day as we spent the whole day on each island we stopped in a rental car so it really didn't matter - we got them to give us a fan and we were fine. I did think we needed a small discount (why not ask??) and had to ask directly for a discount and they gave us $200 on our sail and sign (and our neighbors too since we asked for them) and 15% off our next cruise which ended up being a couple of hundred more since we cruised again on Carnival 6 months later.
I'm not bashing at all it is just that I want you to know that if there are problems (and no vacation is perfect) they can be fixed just ask the right people and GET THEIR NAME!