I stayed at a Sheraton the other night. There's a big sign behind the desk, highlighting their service program, which is basically that if anything goes wrong, they'll fix it. The "Sheraton Service Promise" is the 4th item down. It seems slightly odd that it's not prominent on the website, but very prominent in the hotels. Perhaps they don't want to highlight that things could go wrong.
I never got a wakeup call. When I got downstairs eventually, after being awakened by the room service waiter pounding on the door, it looked like there was some construction was going on. A couple ceiling tiles were off, cables were hanging down, and a workman was staring into the ceiling.
When I mentioned that I hadn't gotten a call, they told me the phone system had crashed. They'd sent someone around to manually knock on doors, and they must have missed me. The desk clerk did a nice job of trying to fix it. They offered the hotel shuttle, and when that turned out not to be available, did offer to pay for a cab, which was a generous gesture.