I would always be leery if I were you, of anyone who does not just offer full certificates for their product up front.
If they don't provide that, chances are its just going to be junk no matter what you do. It HAS to have the authenticity cards and/or original box, for any kind of jewelry/brand new electronics/refurbished products including clothes.
It just makes absolute clear sense, to demand to know whether they have those things with the product from the get-go. Never order anything you are not studied on backwards to frontwards.
You will learn the hard way like maballas, that people are just out to get something from you.