Firstly, even with a few hours notice I will advise the guest that if we can sell the room, they will get a refund LESS admin fees. If of course the room doesn't sell, too bad for them, great for us :) We have had a few put bad reviews on, the usual site of course - Trip Advisor. Firstly I report the review to Trip Advisor as not meeting their posting guidelines, you generally get a generated response along the lines of "..the review meets our guidelines". I then post my management response starting with "This review has been reported to be removed by Trip Advisor" then give the reviewer both barrels making them look like the fool they are. We pay for the business listing in Trip Advisor as well, so I then post an announcement "Trip Advisor allow people who haven't even stayed to review!" We then promptly receive a notice that the review has been removed and can we please change our special announcement. Seriously, 90% of people understand that when they make an error, they wear the cost. I would never bend the rules over a threat