If I buy a new car from a dealer, have a flat bed bring it to my house, stick it in my garage and don't drive it for 15 years, can I sell it as new? No.
The seller described it as new, but it is used. Either ask for a discount down to the average selling price of a used lens, or open an Item Not as Described case.
This is an example of why people have problems on ebay.
If a vehicle has not been registered and you store it for twenty years in hopes of
of its value increasing its still new.
People who have problems on E-Bay just don't do their homework. If this lens sat on
a shelf for fourteen years unused its NEW!
The bottom line if the item was not purchased from a retailer...then it is used by definition. The OP should have known whether he was purchasing from a retailer or not.