Previously purchased songs unavailable for redownload

iTunes 11.4 on Mac OSX 10.9.5

So a long time ago I bought Calgary by Bon Iver but haven't had it on any of my devices for a while. I recently just used "complete my album" and got the rest of the album, but it did not download Calgary.

In the store, next to all the songs it says "Play" because they have all downloaded into my Library, but next to Calgary it says "Purchased" but it is greyed out, and I cannot download it. In the Purchased section it shows no items in the "not in my library" section.

I have found a way to by the song again on its own, but shouldn't have to. In my Library, under Albums, in the Bon Iver album, I can click on the "In the Store" button and under "Top Songs" it is listed for $1.29. But I have already purchased this song individually and have now bought the whole album so I don't want to have to buy the song again if I don't have to.

Thanks,

Evan.