I got scammed where do I report?

I got the necessary screenshots to prove it.
Can someone guide me and show me where I get started?

English please, I don't speak German :)
Thank you

For scammer reports please use: [Only registered and activated users can see links. Click Here To Register...]
A Guide can you find here: [Only registered and activated users can see links. Click Here To Register...]

[Only registered and activated users can see links. Click Here To Register...]