Music sync across devices

In iOS 6 when i bought a song from the iTunes store on my Macbook Pro it would automatically download onto my iPhone into Purchased playlist. In iOS 7 it doesn't download automatically anymore. If i go and find the artist or album on iPhone in Music I see a cloud icon with an arrow but if i click it nothing happens, i have to click it a number of times and it will finally download. Is there a way to get it to do what it was doing in ios 6? Just keep updating my Purchased playlist?