There is none, leave a review in the AppStore or the app you downloaded it from
They usually reply on the Google Play
Not thru a Wiki page, I've had response within the same day on their Facebook page. https://www.facebook.com/afkarena
in your game profile, click Support, click the message at the upper right side, fill in the required fields, after that, click send icon, then this creates a chat box where you can ask questions
What do you think?