I found this which may help you. You said you do have your key right?
How to Download the Windows 8.1 ISO image using a Windows 8 key
Please follow every step exactly as it says. Do not skip any steps or it will not work.
If that still does not work, let us know. We are still waiting for permission on our end to make a move. BK_123 is the one who needs the permission. We both have the file, but my upload speed is to low to be able to get it to you in a timely manner.