If it's this book, How to Paint Citadel Miniatures: Necrons, then you can't sync it to an iPhone, it can only be read on a Mac with OS X Mavericks on it or an iPad - from the book's description page in the store :
Requirements: To view this book, you must have an iPad with iBooks 2 or later and iOS 5.0 or later, or a Mac with iBooks 1.0 or later and OS X 10.9 or later.
If you don't have either of those then you can try the 'report a problem' link to contact iTunes Support and see if they will refund or credit you : http://reportaproblem.apple.com
If the 'report a problem' link doesn't work then you can try contacting iTunes Support via this page : http://www.apple.com/support/itunes/contact/ - click on Contact iTunes Store Support on the right-hand side of the page, then Purchases, Billing & Redemption