There has been a lot of this during these launches unfortunately. I had my Xbox X stolen within the Royal Mail network along with a lot of others, and I've heard of problems with Amazon too.
I thought that Amazon had implemented this six-digit PIN system to stop this after so many Xboxes went missing. They send the customer a PIN which has to be entered on the delivery driver's phone before the item can be marked as delivered. That would seem a good idea.
I hope you get it sorted out. Amazon are normally quite good at getting refund out at least - Game haven't even responded to any emails about mine 9 days later!
no idea about the 6 digit pin or anything, the update just says handed to resident.

Sorry to hear about those that have been shafted one way or another today! I wanted to share how impressed I am with the controller and console etc. But I'd feel like a complete **** for doing so, so I won't. I was stood outside Game with my receipt at 7.30am expecting to be first in-line, there were roughly seventy people foaming at the mouth waiting in-line before I got there. lol.