We are a mobile game development startup and we published our 1st game a few days back and used admob in our games. After publishing the game we have not done any marketing and got only 15 installs so far and only earned around $0.10 USD through that game in admob. However admob terminated our adsense account saying that we did some Invalid Activity and the account can not be reinstated. We are very sure that none of our team members clicked on ads or played the game with the live ads. So I have a theory that some user clicked on our ads multiple times and our account was flagged due to that. We tried to communicate with admob team but we got automated replies.

Now we are thinking of adding another ad network like mopub,chartboost,unityads,etc to our 1st game and the other 2 games which we will be launching in 1-2 weeks. Now the question i have is how can we prevent our account from getting suspended from them, also can we get a account manager from them who can handle our request and listen to our side of argument if something like this happens in future. Our plan is to launch around more games in 2018 and a lot more in 2019 but we are now in a delima which ad network to use.

Admob has a web support section, and details about what triggers their "Invalid Activity" flags.  You are right it can be difficult when their algorithms flag accounts as violating their terms, and that's why companies tend to be extremely careful to ensure the terms are followed. This often includes prohibiting everyone in the studio from accessing the ad-enabled versions of the game to prevent misclicks at your company's address. It also generally includes testing and study to minimize the number of misclicks by end users.

If you have a question about one of those other ad providers, look up their terms on their web sites. Each one has contact information you can use if something is unclear.

I'd also recommend adding telemetry of your own to know when a user clicks on an ad. If you can find and prevent misclicks or other issues, you'll be better off.