Purchased albums not showing up in cloud or hidden section.

Are the versions of the album that you bought still available in your country's store (rights-holders sometimes remove or replace albums), and you haven't moved countries since buying them ? If they have been removed, or you've moved, you will have to copy them back from your backup of your downloads/library, you won't be able to redownload them the store.

Are you've only got the one iTunes account, they weren't bought on a different account - they show on that account's purchase history : If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support ? If they were bought on that account, and you've tried logging out and back into it, you could try contacting iTunes Support and see if they can find why they aren't showing : http://www.apple.com/support/itunes/contact/