I have just got back from my infopasss with the USCIS officer, regarding the non-receipt of my green card matter. They found out that my case has been completed,and mistakenly archived in the national record center,even without production of my green card. Another stupid mistake! So they will have to request NSC to take back my file, and order my card. Thank you,pjang for your advice, and Infopass turns out very helpful.