I purchased a song from the iTunes Store but it won't download?

I purchased "Wasting All These Tears" by Cassadee Pope earlier today. I had about $8.00 on my account, so I used that to purchase it. The money came out of my account balance, but the song won't download. An error message keeps popping up. I thought it was because I hadn't installed the latest update, so I installed it and it still didn't change anything. Next I tried powering it off and back on and that didn't help either. I even reset my wifi. Then I saw on here that someone had the same problem and had to download another song to get the first to download, so I tried that. The second song downloaded with no problems, but "Wasting All These Tears" still won't download. Any suggestions on how to fix it?