I am a german. I take care for this league. I don't accept cheaters.
The answer for all of your question is easy: violations.
Your clan played vs clans he is not allowed to play against, because players from there went to your clan and players from your clan went to their clans. If you have done this within one month, the system will detect everything as violations. All wins will get deleted automatically by the system because of violations. There is no way to get any points back.
In future take care who you invite and ask those people if they played in other clans before. Use the Violation button to see with which clans your clan has violations. The next month starts in 3 days.