Purchased

You 'purchased complete' of what type of item ? If media (e.g. music album) then see if it shows in the Purchased tab in the iTunes store app on your iPad for downloading, or try the Store > Check For Available Downloads menu option on your computer's iTunes and see if that downloads it.

If the purchase went through successfully, and the app and the app doesn't have an IAP (re)download menu in it, then try the 'report a problem' page to contact iTunes Support : http://reportaproblem.apple.com

Or 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