Flying to Asia and knocking on someone's door might not be a bad idea at this point.  You've basically implied that even if they give you a date you can't trust it to be accurate - which says something about your suppliers in and of itself.  I realise that some of the figures regarding the value of BFL pre-orders are probably widely over-stating the reality, but I'd also be willing to bet that the value of this particular contract is significant.  It's not just your reputation and future business which is on the line - your supplier's reputation is on the line too and you can leverage that shit.  

"We'll send you the chips when we get around to it and we can't tell you when that will be" is not an acceptable response and you know that.  I hope to hell you have penalty clauses in your contract because for all your bravado you must realise that this is hurting BFL and that "they won't give us a date" isn't going to fly with your users.  This is a bullet run, FFS.  Some ass needs to be kicked and I can't think of anyone more qualified than you to do it.