Not that this is any comfort to you, but my RTD ND date is Jan 22nd, and my RTD was issued August 1st( didnot get to me until August 8th), after two very unpleasant enquiries with NSC on the phone, the last one on July 16th when NSC customer service was still insisting that my case is within the normal processing time and that their internal system showed I still have about a month's waiting time, despite the USCIS official site listing processing date of March 2nd, or sth. So hang in there but do keep calling/writing them, as no harm can be done, although I am not sure of anything good will be done either.