Gameflip Helped a scammer steal $180 from my account, with fraudulent gift cards. Internet

This is a site much like ebay.... It deals exclusively with video games and digital items (movies, credits, dlc)   I've been a member of this site for over 2 years, and have bought and sold many items with no problem...... However I recently sold a Nintendo Switch that gained me $290 in credit on their site, so using some of it I purchased 2 Amazon gift cards to apply to my Amazon account..... They were accepted and I thought nothing of it..... However 6 days later I received a letter from Amazon saying that my 2 gift cards were fraudulent and they would be cancelling any orders and if anything like this happened again they would Cancel my Amazon Account!!! So I've told Amazon of the situation and I've told Gameflip of the situation, neither is doing anything.... my money is gone, I have nothing and both companies and the seller that sold me the fraudulent gift cards tell me there is nothing to be done!  Not to mention that the seller has been, and is still, selling Amazon gift cards.... and at this time has sold over 280 of them!!! That is why I'm reaching out to you.  Thanks Patrick