Downloading Keynote app is stuck and "waiting"

I have a MacBook Air OS X Yosemite 10.10.2, I bought the Keynote App and the downloaded started. But it got interrupted because I lost internet connection. So it only downloaded 150MB. I clicked on "Resume" and it is showing that it is "Waiting..." for several minutes now. I restarted twice but still cannot get it to continue the download. Your help is appreciated.