While you did not say which "online auction site" you used, it is a well know secret that many fake forever stamps are peddled on eBay
. Real forever stamps too show up on eBay
at the same discounted pricing and are likely those which "feel off the truck" or left via "the side door" or otherwise "liberated" from a unsuspecting former owner.
It is so bad now a days, the main US Stamp Catalog, Scott Specialized Catalogue of United States Stamps & Covers has pages of entries of counterfeit stamps produced and sold to the public.
What you purchased should show up eventually.