Frank offers three Hospital covers: Basic, Better and Best.
And two Extras covers: Some and Lots.
On the Extras covers you can choose whether you get 50% or 80% back.
So simple, in fact, that this video about Frank's covers only took Frank 48 seconds to make. (Quite a feat, given it's 1:03 long.)
Watch, and be enlightened.
FrankView video: Frank's covers