we did sign on white paper
--- If the case is approved and no problem then officers takes your signature and Fingerprint on White Form (that form is used for Card production) and sends that form with your file.
, and also we had been fingerprinted 2 weeks before the interview
---This is different Finger prints for security check as your FP may have been expired
, i took info pass appointment where they did not reveal lot of information just said waiting for visa number, when i pointed my PD is current, they took all the information on a green form and said they will investigate.
---when you visited local USCIS with Infopass you you met someone at Wndow and they dont know much. You should again take infopass and ask for the Supervisor and explain your situation. Take evence of your PD being current and the date your interview was conducted and Copy of your I-485 filing receipt. Most of the time if officer in new who conducted your Interview has to get the approval from supervisor. May be your case file is still pending approval from Supervisor and file is still in local office. you should go to local office and meet the supervisor and they can locate your file with your A#.