Don't waste any time or way to get the RFE and reply at the earliest. Reason is normally USCIS will give only 12 weeks to reply. I understand in the RFE they mention that, if they don't get the response within 12 weeks they would consider your case is abondoned and a possible denial.
I'm not trying to scare you.
Try sending letters or fax to them or a supervisor, instead of just talking to the rep in NSC 800 number. May be your attorney or you could go to the nearby center, meet a officer to get the details and resolve it.
Good luck.