I pre-ordered GW:EN through Amazon UK a few weeks ago as it included a key for the preview event. Throughout the week running up to the event I exchanged a number of emails with customer services as to the wereabouts of my pre-release event key.
At 11am on Friday I emailed Amazon customer service putting it rather bluntly that if I didn't have my pre-release key in one hour they could kiss goodbye to my custom for some time.
An hour later after no response I cancelled the order, bought a pre-release key in the GW store and pre-ordered the game from Play.com.
Play have dispatched it and it should be dropping on my mat today (living in the country means deliveries can appear at any time).
As an aside:
I recieved a notice of cancellation from Amazon on the Saturday of the event weekend, it informed me I wouldn't be charged for my cancellation, and, if I wanted to order GW:EN again, my pre-release key would be emailed to me within two weeks. Marvellous, well done Amazon. I didn't bother to check & see if they included instructions on how to go back in time to use it!
Vedict.
Play.com 1
Amazon.co.uk 0