Two points: 1. This is not a problem with Google's Customer Service, it is a problem with their vendor relations. When Google publishes ads on your site, you are selling that space to them. Google is your customer and isn't obligated to tell you a damn thing except that they don't want to buy from you anymore. 2. There is a market opportunity here for an ad network that is willing to find good sites dropped from Goog…
While you make valid points, the major issue in question is Google's lack of customer service for the advertisement brokerage service they provide. Google may not have to "tell you a damn thing", but they should at least make themselves available to deny any requested information.
And yes it sucks; but there must be advertisers out there who think that a site that gets 10,000 impressions a day and is linked from most of the popular news sites is worth something; selling to them is a better move than whining about how Google doesn't love you anymore.