Purchased Music in iTunes - Pending ???

I purchased a song in iTunes on my MacBook computer and I can see it under my list of purchased songs / albums, however, this song says pending and wont allow me to transfer to my playlist. I used my iTunes card which was already on my computer, it shows me my balance so I definitely had enough $ on it.

What is the issue? - I have bought other music from iTunes this way and never any issue with my music being transferred to my playlist so I can listen and enjoy.

Does anyone know what 'PENDING' means? Why is it there on a purchase that has been completely paid for on an iTunes card? How can I remove the pending and transfer my music to my playlists?