I recently had a poor experience with this.

Booked "Hilton Long Term Stay" rate for one week. The terms and conditions are: "Change or cancel up to 5 days before arrival. Stay longer and save up to 15%. Early checkout or a reduction in number of nights, may result in a rate change." The third clause implies that modifications after arrival don’t automatically trigger a cancellation fee, but might result in a higher nightly rate. The key word is "may result in a rate change," not "will result in a cancellation fee." It anticipates that a shortened stay is still a stay, just potentially at a different (likely higher) nightly rate.

On the day of arrival, I had a change of plan. To avoid the cancellation charge, I called hotel to change the reservation to a 1-night stay and intend to stay for one night. Hotel told me any change to my reservation will result in 1-night cancellation fee. I complaint that the hotel was not honoring the published terms and condition. They would not budge, so I canceled the full stay, paid 1-night cancellation fee and raised the issue with Hilton Corporate guest service. Hilton corporate refused to help and was extremely unhelpful. They basically refused to acknowledge my interpretation of the stated policy and told me to contact the hotel.

By allowing its hotels to not honor an option available under the stated policy, I view this as unfair or deceptive business practice. If anyone has info on how to escalate this matter beyond Hilton Corporate guest service, please let me know.