There is a topic over at WebmasterWorld named Thrown out-any right of appeal? This is about a story of a publisher who was removed from the Google AdSense program because Google believed click-fraud was going on.
Of course the individual completely denies any wrongdoing. He has tried to appeal and is awaiting a response from Google.
This actually brings up an interesting discussion on how Google should treat its ad publishers. The bigger the publisher the more personal touch...
Also, the discussion gets a bit into how one can be a victim of fraud.
If a rival company wants to take down it's competitor one of the best ways to do it is to make them leave internet advertising. To do this they use spam software not to click on ads to generate cash, but to drain their competitors advertising budget. If they use crawler software to scour several on-topic sites for their competitor's ads and click on them repeatedly then their competitor loses money and faith in Google Adwords. Obviously a few sites lose their account with Google because of it but what do the rival care? You can bet that even though you were kicked off for fraudulent clicks, the advertisers that were 'de-frauded' won't get their money refunded.