(Travel + Leisure) -- A couple of years ago, online travel-booking sites such as Expedia and Travelocity began issuing service-related manifestos -- the idea being that you could contact them with problems before or during your trip, much like you would a travel agent. But read further, and you'll discover that these are promises to provide good customer service, and aren't built to protect you from the fees and penalties you may incur due to last-minute cancellations. In fact, I've heard more complaints than ever lately, probably because we generally associate words like promise and guarantee with money back. Case in point: Roberta Sherman, a Travel + Leisure reader from San Francisco, recently booked a hotel stay in Cancún for $430 through Travelocity. When she missed her connecting flight from Dallas due to bad weather, she immediately called Travelocity to let them know she wouldn't make it to the hotel that night. Travelocity, in turn, told her to call the hotel, but despite the circumstances, she was charged the full amount. Could she have done anything to avoid this? Prepaid rates might be cheaper, but they come with tight restrictions Sherman had booked a room marked with a Travelocity "GoodBuy" tag. She prepaid the reduced rate, which had a 48-hour cancellation window. Expedia "Special Rate" hotels work similarly, in that you pay at the time of booking. But if you cancel or change your reservation with less than 72 hours' notice, you'll have to fork over a fee that's generally equal to the first night's room charge plus tax. According to a Travelocity representative, the guarantee to "make things right" kicked in the moment Sherman called from the airport. But since the agent reminded her of the penalty at the time of purchase and she agreed to it, they didn't feel obliged to negotiate a refund (after much persistence, however, she was reimbursed -- two months later). Lessons learned: Prepay only when the rate is a significant savings, and read regulations closely. Cancellation policies differ, especially with multi-component bookings Another T+L reader, Marcy Soltis of New York City, booked a Las Vegas air-and-hotel package through Orbitz in January 2007. When her midmorning flight was canceled, she called the site for help. After waiting on hold for 2 1/2 hours, an agent finally told her that Orbitz could refund the hotel charges, but that she'd have to deal directly with Delta concerning her flight. SOURCE: CNN.COM