Yeah it's the MDNA (Deluxe Edition) which was pre ordered in February. When checking the pre-orders in the itunes login section, it state that the album is no longer available, I know that the order whent through as they charged me for the single download and said the rest will be taken today.
Same problem here. From the Italian Store, so this should be a worldwide issue. Till yesterday I had always the message from iTunes on iPad that the download isn't available. Now no message but no download in any case.