I pre-ordered a book from Amazon.co.uk and the estimated delivery time is RIDICULOUS?

I pre-ordered La Toya Jackson's new book on the 18th of this month and it comes out today. The estimated dispatch time is 4 July 2011 - 7 July 2011 and the estimated delivery time is 7 July 2011 - 13 July 2011 and the current status is 'Not dispatched yet'. Why should it take more than 2 weeks to get this dispatched and delivered to me? I live in the UK so there shouldn't be a problem with it getting here on time. Are the estimated times usually accurate? If so I will never be ordering from Amazon again.