I would be eager to download and listen to a pre-ordered album as well. I found a couple of resources that might help with downloading this purchase.
First, I recommend trying to download the album from the list of past purchases. As long as you are signed in with the same Apple ID you used to purchase the album, you will not be charged again. You can find the steps to do this in the section titled "Apps, Books, Music, Movies, or TV shows on a computer" in the following article:
If you are still not able to download the album, I recommend reporting this issue to the iTunes Store:
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