Ask yourself:
How exactly would one contact the Immigration Information Officer at the District Office other than through an infopass appt.?
What can I find out over the phone?
What can I find out at an Infopass appt.?
If you find out that you are scheduled for something but didn't get the notice, you may be able to get a replacement copy of the notice at an Infopass appt. and if there is enough lead time perhaps via the phone inquiry.
If you are scheduled for FP, an interview or oath and know it, well unless you have to request re-scheduling there would be no need to contact anyone.
Over the phone: If you didn't know about any appt. until this inquiry because you had been waiting patiently but didn't get a notice (did you miss an apt. that you didn't know about? was your case Admin Close as a "no show"? is it lost in the mail?, is it on the way right now?). If you hadn't inquired then you could not takes steps to make sure you could arrange your schedule so you could make it to the appointment, request re-scheduling, request re-opening an Admin Closed case, or request a re-print of the Notice of a pending appt. (and perhaps ask for it to be faxed depending on who you manage to contact--that's rare).
Keep in mind that the Info Officer that you would see during a Infopass appt at the DO will usually not pull your file from its current location even from within the same building. This is because early in the process, if the file has made it to the building, that generally means that it is scheduled for an interview or Oath Ceremony and should not be pulled out of line. In this case that Officer couldn't tell you anything other than what is on their computer screen. That is the same info you can get over the phone and the same info displayed in case status online.
If the Information Officer for your Infopass appt. sees that you have already been interviewed and do not require a re-exam but have not been scheduled for Oath, and that you have submitted documents for review, they may be able to tell you if
the file has been given back to interviewing officer for review or
if it still sitting in the mailroom/fileroom waiting to be given back to the interviewer, in this case, if you have a return receipt card from the post office showing it was received in a DO and show that at your Infopass appt. at the DO but the computer does not show that it was placed in the file yet, it depends on how much time has elapsed to see if you'll get any response other than "wait another...." The Info Officer will have a pretty good idea what is normal in that office and MAY go look into the physical file.
If you are a worrier by nature you might want to make sure that your response to your N-14 request for evidence was received. That info might be updated in the computer by a mailroom clerk when they place it in your file. Sometimes that gets missed so don't be overly concerned. You can bring another copy of the response to your Infopass appt. but that is rarely ever needed. It makes some people "feel better" to do this but is usually just a waste of time, effort, money and paper.
If your case is in one of the classes of cases that require supervisory review*, the Info Officer may be able to tell you if the file has been given to a supervisor to complete the review or if it still waiting to be assigned to a supervisor for review.
*Interviewed on a T-file (Temporary file---this is rare nowadays),
*Involves an N-648, Medical Waiver, or
*Most FP Ident cases (these are usually criminal histories with FBI Rap Sheets)--some civilian fingerprinting like for a security clearance for employment may show up but can skip supervisory review.
After all the substantive adjudication steps are done and an Officer stamps your N-400 either Approved or Denied, there is a final step before either the Oath is scheduled or Denial is mailed. That last step is a quality assurance review of the processing steps. This is called reverification. It is not a readjudication of the merits of the case but merely a check of the multitude of processing steps and associated annotations on the processing worksheets.
Are the fingerprints valid?
Did the officer note the following?
-the english and civics test was passed or waived,
-the court dispositions were requested and received,
-the oath and certificate prep sheet signed
-etc.....
Carefully consider the particulars of your case and think to yourself:
What steps does my case still have to go through? Have I given it sufficient time to move along or is it stuck?
Can I get good enough information online?
Over the phone?
Or do I need face-to-face through Infopass?
Can a Congressional Inquiry do any good?
Do I need to take them to court?