Kerry, I feel for you! It's extremely frustrating when trying to deal with a large business. This is something we deal with all the time and it never gets easy. But this is the main reason why it's best to book with an agent - they have access to contacts you don't have or can't get to without alot of hassle. Plus, you're just one person and depending on the agent, they can have a great deal of support behind them. I can't tell you how often I've heard complaints like yours and they always feel like they're hitting their head against a brick wall. One commonality about big business is that they have the overinflated sense that if they ignore you long enough, you'll just go away.
So, with all that said, the only thing I can offer is my support for your task. Based on what you've said, you definitely have the right to complain because you were not provided what you (or your family) bargained for and you deserve restitution. It's too bad that hiring an attorney in this case would not be prudent given the amount. And I know that it may not be worth it to you in the end because of the time you'll probably be investing, but if you want satisfaction, you really need to hang in there. Remember the adage about the squeaky wheel getting the oil. And here's something to think about; the cruise lines have contracts with companies whose sole purpose it is to monitor social networks to see what people are saying about them. Sometimes it doesn't hurt to make noise in obvious places.