AI Wars: Fleet Command - Where is my Licence Key (Mac)? Thread

I have the full/paid version of "AI Wars: Fleet Command". When I download the game (Mac OS) and try to play it, it tells me that I have the trial version and I need to enter the licence key to unlock the full game.

Am I missing something obvious, where do I get my licence key?

(I have tried contacting Desura support (both via the online form and later via email) but it has now been over a week and I have not got a response back.)