Can't download something I've bought

[franc1]

I am new to Spotify.  I've bought three tracks, two of which seem to have automatically downloaded, but the third hasn't. When I click my personal tab (top right hand side of screen) the item that tells me I have purchased downloads which are not yet in my library is grey, rather than black, so I can't click on it.  I've tried clicking practically everything else to try and work it out for myself but am stumped - and very frustrated.  Any advice?