I will suggest you to contact them through their bitcointalk account first and then if they do not make any response on your PM then don't forget to share updates here again. Proper scam report format have already been provided by previous poster. Just follow the format and add all details information by which we can understand actually what happened with you.

Here is Betnomi Official bitcointalk account; https://bitcointalk.org/index.php?action=profile;u=2532772