But it happens. I was "walked" from a Hilton property some months ago. I asked Hilton corporate if I could have points/stay credit for the property where I'd booked and an exec said he'd take care of it personally; sure enough, they posted on my next statement. But about three months later I got an auto-generated letter from HHonors saying those points were being taken off my account because they "could not verify" the stay at the property in question.

I figured it was too few points and too complicated a story to argue, so I gave up. But audits DO happen.