I've used many times, and have been happy with it. I'm also a former airline employee and seasoned traveler, so I am not ignorant of the travel industry. But I'm having some trouble with Hotwire's star ratings and could use a little help from you.

I am driving to Chicago for a convention in a couple of weeks. After confirming the area I wanted to stay in, I checked the star ratings to make a choice in hotels.

The only hotel I did not want to stay in was the Hilton at the airport. Hotwire shows the Hilton rated 31/2 stars, so I chose a 4-star option in the area.

Needless to say, the hotel I got was the Hilton O'Hare. Hotwire informed me that it had just changed the rating for that particular hotel to four stars and would not change my reservation per their rules. I tried to explain that they still had Hiltons listed as 31/2 stars, but to no avail. The hotel Web site lists the AAA hotel rating at three diamonds. The customer service rep said he does make exceptions but would not in this case. What should I do?

- D.B., Eagan, Minn.
Answer: If you asked for a 4-star hotel, then Hotwire shouldn't have given you a room at the Hilton. The representative you spoke with should have changed your hotel immediately instead of arguing with you about an "exception."

It helps to understand how Hotwire works. The site offers airfares, car rentals, and hotel rooms at deep discounts, but you don't find out the name of the airline, car rental company, or hotel until after you've booked. A ticket or room bought through Hotwire is referred to as "opaque" because you only find out a few details about it before you commit to buying.

In your case, you could specify the neighborhood and amenities, but not the actual hotel. Like other travel sites, Hotwire rates its hotels with stars, which denote the types of amenities you can expect. The difference between a 31/2- and 4-star rating is slight. A 31/2-star property is described as a "classic, polished" hotel featuring a "well-known, on-site restaurant and "large, quality rooms," while a 4-star resort is described as a "distinctive establishment" with "gourmet dining" and guest rooms with "upscale furnishings, bedding and bath products."

The full description of Hotwire's star ratings can be found online at: gs-faq.jsp.

For what it's worth, Hotwire cited Hilton properties as an example of a 31/2-star hotel when I checked.

This is the type of complaint resolved more easily with e-mails than phone calls. A brief, cordial note to Hotwire with screenshots attached should get the job done. But your written request to review Hilton's star rating was met with a form response, insisting that the company stands by its current rating and refusing your request to move to another property.

When a company digs in its heels, you have a number of other options, including a credit-card dispute, a trip to small-claims court, or a note to yours truly. I contacted Hotwire on your behalf, and it agreed to change your hotel.