Strike Suit Zero Soundtrack?

I recently bought the strike suit zero mega bundle on steam, now after playing the game for a little bit I realize I love the music, so I was going to download the soundtrack, but when I go into the game under the downloadable content section of the main menu it says I need to buy the soundtrack again, even though I know the game recognizes that I have the DLC's so how do I access the soundtrack and artbook because I am having the same problem with that