I cannot get a song to sync or download on to my iphone5s

Hi

I purchased 10 songs at once and I cannot get one of them to download to my iphone5s. I have tried syncing my phone to the computer. I have tried to use the cloud icon on my phone to download on to my phone. I cannot figure out why this one song will not download. It is checked on my computer to sync. I have gone on to the itunes site to see if re-downloading it however it just says purchased. Any suggestions?