I'm in the same exact position, I ordered by phone called at 7 am set when they opened and was only told the terms had to be accepted before it would ship and was told it would ship 9/20. Didn't tell me that my order didn't really count until I accepted though. I actually didn't realize it was in my spam folder until I go looking for it the next day in the afternoon. Now my order date says 9/15 so I'm even later than you. I've been told from a live chat it goes from when you accept, but I've also heard people say it still goes by when your order # was created which was the morning of 9/14.
Who really knows, mine still says its backordered. I'm pretty pissed also and if it doesn't ship this week I will be trying to have the upgrade fees waived ,the whole point of calling them as soon as they opened was to get it Friday. We had to ask to upgrade one of our lines early otherwise we would have ordered online.