The same thinbg happened to me about the being slammed.. I got banned about 2 years ago and a long timer slammed me pretty hard to.. This one was also suspended around a year ago.. Probably the same person.. I did some research and found that if you had a substantial gain in a single month like I did then this may be the reason.. I have talked to other people who have had the same thing happen.
Google has an algorithym that is not perfect... but it is getting better. I hear these types of stories all the time.
sorry for hearing that. maybe there is someone who jokes with you and always clicks your sites ads again and again, so google thinks it as invalid clicks.