Mistakes happen. Things come up that are unexpected. Most people get it.
That said, taking a minute to send out an e-mail or a simple post to facebook, etc. would have been nice (and expected). When people spend a lot of money, are already waiting a long time, and are told to expect something "immediately".... I can see where they are frustrated by A.) not delivering on the deadline..... and, much more - B.) lack of simple, easy communication as to it not happening.
Not the end of the world. But, there was a REALLY easy way to head off the questions, concerns and frustrations.