I had a similar issue with Amazon recently.
I ordered a PC game and paid the postage to, hopefully, get it on day of release.
Day of release... nothing. Despite their site stating the item was now in stock and 'usually dispatched in 24 hours'.
I emailed them asking for an update, and was informed that they had no stock, but were happy to inform me that they had secured a copy for me! - Rather contradicted what their website was stating.
I replied stating their stock/availability system was misleading and asking why I had not been informed of the delay (bearing in mind I had recently ordered Halo 2 and received an email from Amazon stating a delay), their reply was 'You get one email confirming order, and another confirming despatch'!
I finally received the product about 4-5 days after release.