Whatever your company is trying to accomplish, banning developers who have been longtime partners with absolutely no explanation is probably not the way to go about it.
I’ve had a similar experience as the other commenters. After working with Chartboost for over 4 years and earning hundreds of thousands of dollars together, my account was suddenly banned on suspicion of fraud.
I can tell you that not only have I not committed any fraud, but I have not touched the games in the account for years. I have no idea what kind of fraud may have happened, but if you guys are facing a problem, I would have appreciated a conversation to see how I might be able to help, rather than a wild accusation followed by absolutely no communication when I reached out.
At this point, I am no longer interested in doing business with Chartboost, nor can I recommend your company to any of the numerous entrepreneurs who ask my opinion. Hope that you learn how to communicate with your customers and partners much better going forward. Best of luck.