Take the cooler off and take a pic of what it says on the GPU. Its very rare to happen but not uncommon for a graphics card to have a vBIOS thats not fully functional but the only cases like that I've heard / seen are ES samples. As this card is supposed to be OEM, who knows, maybe its just got a ES vBIOS on it. Its a long shot though, I think you have more than likely been duped.