QI recently booked a vacation rental in Monte Carlo, Monaco, with Airbnb. The place I booked had a strict no-change policy.

About three days later, I realized I had made an error in my dates. I contacted the host through Airbnb and asked if I could change the dates. I was still going to stay the same number of days, but just needed to shift the arrival and departure within a 10-day time frame.

The host said I could do it. I have it in writing. I just needed to fill out a formal change request through Airbnb.com.

I did as she asked. A week passed, and the host did not accept the request. I contacted her, and she told me she no longer could accept my request because she had a new booking, and that I had to honor my original dates.

I changed my whole trip based on the fact that she told me she could accommodate me. So I asked her if I could cancel, and she said yes.

I contacted Airbnb, and the company has refunded half of my money. I have not been able to get all of my money back, and talking to customer service is a joke. Everything is documented — all of the conversations, as well as my request.

It’s been more than a month, and I can’t get anyone to help me. Can you convince Airbnb to do the right thing?

MICHELE PALANZO,

Danbury, Conn.

AThe terms of your rental are clear. The “strict’’ refund policy — you can read the details on Airbnb’s site (www.airbnb.com/home/cancellation_policies#strict) — says you can get a 50 percent refund up until one week prior to arrival, less fees. And that’s exactly what you received after you canceled.

But it also says Airbnb’s cancellation policies may be superseded by a guest refund policy, safety cancellations or extenuating circumstances. I would argue that a written agreement stating that you could move your dates would fall in that category. Once you showed Airbnb proof that you were told you could change your dates, you should have received all of your money back.

Your host apparently wanted to pocket your money and the money from the new booking — in other words, to double the money for the rental. That’s wrong, and it should be illegal.

Airbnb insists it never meant to keep the $800 it failed to refund you, but that the money hadn’t been refunded because of a “system error.’’ You’ve received a full refund.

Christopher Elliott is the ombudsman for National Geographic Traveler magazine. You can read more travel tips on his blog, elliott.org, or e-mail him at chris@elliott.org