"How do I report a scammer to the admins?? "
You click on their username and then select 'send a PM' from the dropdown.
They're officially not in the business of rooting out scammers (that's what funds with buyer's protection is for), per the
sticky on the top of this very subforum, so read that set of rules and set your expectations accordingly. Also in that rule post is instructions on how you can post in a way that both notifies the Fauna community and doesn't run afoul of the rules in the way that this current thread does.