I am an author who has been approached for a joint project with Amazon Studios and Stage 6 Films Division of Sony Pictures Entertainment

I am an author who has been approached for a joint project with Amazon Studios and Stage 6 Films Division (Indi affiliate of Sony Pictures Entertainment) They want to create a film script for one of my books. I have had success with the Amazon contact (they produced a professional quality film trailer for me), but have never met him or the contact at Stage 6. They have each provided signed agreements, but want me to provide an refundable $8,000 retainer to "demonstrate my commitment". I have some trust for the Amazon Rep, but neither are willing to meet via Video Conference, claiming that would violate their non-disclosure agreements. I am simply trying to verify the actual people as being connected with these organizations prior to proceeding. Can you assist me?