preorderd album

I preordered the 'Pray For The Wicked' album by Panic! At the Disco around a week or two before it was released. I immediately received three of the songs which were already out. Now that the album has officially been released i expected to see my songs in my iTunes library. When I didn't, I checked my emails and saw a confirmation that it was ready to download. I clicked on the link and it took me to iTunes and after entering my apple id and password, it said that there were insufficient funds to complete album. I have already payed for it and was wondering why I am unable to download my songs.