Thanks for the support, Stoatula... it's very much appreciated. I don't have a lot else to go on right now. It seems like there's now way of actually talking to a REAL person at the Consulate... all I can do is go through Worldbridge (at $12 per call!), and they appear to know less than I do about the process (and of course aren't able to go and look for a package in the Consulate's mailroom). I do appreciate the need to screen calls going to the Consulate, but you'd think there'd at least be some way of them putting me through to someone who can help, once I've demonstrated that I have a genuine reason for needing to talk directly to the Consulate. It's all a bit of a nightmare at the moment... hopefully I'll wake up soon!
VictoriaS - just saw your post. I've just finished a letter to the Consulate (maybe they'll acknowledge it's arrival this time), and I've cc'd my MP (I'm British, my partner is American), so we'll see what happens on that front. Thanks for the suggestion.