The lens you received has a serial number which has not been issued by Sigma’s factory in Japan. It appears that the lens you received is a “Grey Market” lens, and has been tampered with having its serial number changed. This would explain why you received no factory warranty card with the lens; the serial number printed on the warranty card at the factory, would not match the number on your lens. The Sigma lens should always be supplied with the factory warranty card, which is necessary to help verify the factory warranty. This altered serial number has implications for the Sigma one-year warranty. We suggest that you contact the dealer regarding this situation, immediately.