Seven days later, after multiple broken promises for "delivery the next business day," offers to refund, and subsequent refusals to refund, I finally received my order in my wallet.
It popped up in my "unconfirmed" balance moments after I sent a support message saying my next visit was to file a complaint on the BBB's web site.
Probably just a coincidence. Regardless, thank you Bitinstant for finally getting this resolved.