Send a letter to Carnival corporation via www.planetfeedback.com
if your were dissatisfied.
I have to say I've been on 2 Carnival Cruises and my 3rd is booked in March. I've had good and I've had bad experiences but you have to make the best of it. I wouldn't worry too much on what OTHERS went thru either. So what they were stuck on the boat (they could have gotten off and found something different to do in Cozumel). You just can't expect to get a free cruise out of a bad experience not within Carnival's control. It's not like they planned this all to ruin your cruise. In life you have good and you have bad, it's what you make of the bad that makes ALL the difference.