I’ve had this very annoying problem where rentals won’t delete from my iPad, even well after the expiration date. They just sit there taking up precious space, and there’s no way to remove it. Luckily I found a way to remove it, and without having to jailbreak it.
The solution for removing rented movies on your iPad, iPod Touch or iPhone is actually very simple. Plug in your iOS device, go to iTunes, and then view the Summary page. Under Options check the box next to “Manually Manage music and videos”.
Apply the changes, and then expand the list view for your iOS device. Click on Rentals and then delete the movies.