Their answer about "ask Ebay ..." IS weird. eBay doesn't vouch for anyone. They do not confirm that items are authentic. They do not check out sellers before they are allowed to list on the site.
Just wait until you get the purse and at that time post pictures of what you receive on the particular brand authentication thread.
Just wait until you get the purse and at that time post pictures of what you receive on the particular brand authentication thread.