A few months ago, I tried to book three flights to Florida through Expedia. But during the confirmation process, my computer froze and the screen blacked out. I called Expedia to verify that the flight had been confirmed. It had no record of my purchase, so it offered to help me make the reservations by phone.

Instead, I returned to its Web site and rebooked my flights. This time it worked.

But when I received my credit-card bill, I saw charges for both sets of flights. I immediately called Expedia to explain the error and to cancel one set of tickets. A representative informed me that there would be a $100 cancellation fee per ticket, and the tickets would have to be used within a year of the purchase date. I feel that this is unfair and unacceptable. Is there anything you can do?

- A.L., Johnsonville, N.Y.
Answer: Expedia should have recognized the double booking and refunded the first ticket. When you called the company after your PC froze, the agent you spoke with probably made a notation about your attempted booking. All Expedia had to do was check its own records.

Your story is a reminder that when it comes to travel, the Internet is far from perfect. Not only can a booking go wrong on the online agent's side, but wires often get crossed on your end, too.

Like a screen going black. You know you're in trouble when that happens. It sounds as if you experienced a power outage.

Phoning your online agent immediately was the right response. But I would have done three things differently. First, I would have accepted Expedia's offer to buy the tickets by phone. Also, I would have asked the agency to note your failed attempt to book through the Expedia Web site. That way, if the first reservation got processed, you would have the evidence that you did your due diligence.

And finally, I wouldn't wait for your credit-card bill when there's a chance of a double charge. Monitor your credit-card account online, and contact your online agency as soon as you see a problem charge.

Expedia's reaction to your request for a refund was wrong. Rather than quoting you chapter and verse from its rules, it should have investigated your case more thoroughly. When an online agency isn't taking your request seriously, you need to take your case to a higher authority. A few executives at Expedia who might have been able to help are listed at www.elliott.org/help/expedia.

I contacted Expedia on your behalf, and it refunded the price of your first ticket.