I think the way to handle this is to post the reviews on trip advisor. If the hotels are a part of a chain post reports about lack of customer service in the relevant forum. The issue isn't not providing an early check in, it's the attitude of employees. Shrugging and pointing to a sign is a complete customer service failure IMHO. I do read hotel property trip reports on flyertalk, and tripadvisor. And when I see patterns of poor customer service I avoid those properties.