After reading this post on Bible Money Matters, I couldn't help but think of our own similar experience:

Ryan and I were traveling to Atlantic City for a mini-vacation after we checked out housing for a job offer he received, and had booked a stay at one of the casino hotels via their online booking website. We had been to Atlantic City before, and by entering our players numbers were able to get a few comped nights.

Awesome - free rooms, in a cool hotel, what more could we ask for?

So we get to the hotel and start to check in, when we are told that we have to pay for Saturday night and that they "don't allow comps for Saturdays." We were confused, we had the confirmation online and when we "checked out" the total was $0.00 not $150+ for Saturday night. We tried to reason with them, explaining how the balance was $0 and how we wouldn't choose to stay here if we had to pay the full price, but they kept saying the charge wouldn't show up online and would only appear when we checked in. Of course this didn't make any sense to us, and we kept fighting for the arrangement we agreed to.

After a while we tried to find the printed confirmation email and code, but of course we forgot to bring it with us. Luckily we had our laptop, and were able to sign on to our email via their wireless system (after paying the $20 for 24 hours connection fee) and showed the manager our confirmation which clearly showed all nights, including Saturday, free of charge.

The manager looked it over, hesitated, and was still saying it shouldn't have been possible - that this was completely unheard of, especially for people like us who didn't come down and play regularly- but eventually she admitted that our email verified what we said all along, and she let us have all nights at the comp rate. The whole ordeal took about an hour of talking to several different people and trying to figure out what happened while staying civil after traveling all day.

The moral of the story? Make sure you bring your confirmation numbers, and make sure you actually get the deals you sign up for. Double check that what you are paying is what you agreed too. In our situation it was obvious because we intended on paying nothing, but I could easily see fees and other charges getting tacked onto a bill without the customer noticing. Caveat Emptor.