Q: Last fall I took a Caribbean cruise on the Carnival Destiny with my family, and I was very disappointed by it. Before the trip we decided to add another person to our cabin. I called my travel agent to make sure we would have three beds and not two beds with a cot or a rollaway bed. My agent assured me we would be rebooked into a cabin with three beds.

But when we boarded the ship, we discovered that there were only two beds. We were offered a rollaway but I refused because there was no room for it. I notified the purser’s office and called my travel agent from St. Thomas. Fortunately, my brother had an extra bed in his cabin, and I decided to stay there. My agent promised she would get some of his fare reimbursed, since he had paid a single rate for his cabin.

Since I’ve been back, I have not had any cooperation from Carnival whatsoever. The cruise line has offered us a $50 certificate towards our next cruise. I’m not happy with that. I paid $550 for the cruise and a bed to sleep in and I feel I should be reimbursed for the full amount of the cruise.

– Dolly Dawkins

A: If you booked a three-bed cabin, but didn’t get it, you’re entitled to some kind of refund. The question is: How much – and who should pay for it?

I asked Carnival for its side of the story. According to the cruise line, your travel agent made a group reservation for your family. Because your travel counselor wanted to secure the best possible cabin for you, she waited until shortly before your sailing to give you a room assignment (that allowed her to secure an upgrade for your family).

When three passengers occupy a cabin, the third berth can come in one of two forms – either an upper berth that pulls down from the wall or a rollaway. If you get a rollaway, then it’s normally brought in during the evening turndown service and then removed in the morning so that it doesn’t clutter your cabin, according to Carnival.

“If there’s no specific cabin assignment, then it’s a crap shoot as to whether they will receive an upper berth or a rollaway,” Jennifer de la Cruz, a company spokeswoman, told me. “It just depends on what is in inventory within the section of the ship where that group is being berthed at the time cabin assignments are done.”

Carnival’s records show that during the voyage, a representative from the cruise line’s groups department e-mailed the ship’s chief purser to request your cabin be switched (this was probably in response to a call from your travel agent).

According to the pursers’ office logs, a note was left in your cabin asking you to contact the purser. De la Cruz also told me that “multiple phone calls” were made to both your cabin and your brother’s, with no answer.

“The bottom line is that Ms. Dawkins received what was booked and paid for,” she says. “Carnival did not fail to provide the third berth, but did in fact provide what was booked.”

Carnival appears to have done the best it could to accommodate you during your cruise. I think there may have been a disconnect between you and your travel agent, though. She obviously shouldn’t have promised you a berth with three beds, because Carnival couldn’t guarantee one with the kind of booking she had made.

You might want to consider taking the matter up with your agent.

Is that reason enough to get rid of your travel adviser, or replace her? No, I think this was probably an honest misunderstanding. And as I’ve noted in the past, a good travel agent is worth every penny you pay in fees.

But I’d strongly recommend that the next time you take a cruise, you should pay closer attention to the type of booking you have. It wouldn’t hurt to confirm your room assignment with the cruise line instead of relying exclusively on a third party. Not only does it give you peace of mind, but it also ensures that your wires won’t get crossed the way they did.

In addition to $50 shipboard certificates, Carnival also offered you a 50 percent refund and a 50 percent discount on a future voyage. Although that was the result of an air-conditioning problem on the cruise, and had nothing to do with your case, it’s extremely generous. Bottom line: The cruise line has already given you $275 and a $50 voucher, plus another coupon worth as much as $325.

I think Carnival has done enough.