100% if it is fake. Get a professional authentication for $10-15 that verifies that it is fake. File for a return through your purchase history (maybe under a tab saying something like “other options”?), and choose the reasons that it “doesn’t seem authentic” and attach a photo of the non- authentic document. You will then get emails telling you the next steps. The seller may never respond and eBay may never take the next step, so when the date comes that they say in the email, contact them if need be. I usually have to contact them a few times if the seller is trying to ignore the case and make it go away. However, you will 100% get your money back if it is fake, regardless of the seller’s return policy.