I had a long fight for NC, and a clerk at my local congressman helped me out with FBI. She was very helpful and really shared my feeling on this lengthy immigration process. I got an FBI email forwarded her, indicating my completing date and my wife's status.
I used it to challenge VSC which was saying my case pending on my NC, later saying pending on my wife's since we are together (ridiculous).
NC is a painful process if u stuck there. No effective way to really know what is going on your case.