Yes I DO realize that it's just a license that I was using. But just like when I purchase a song from Itunes for my ipod, there is nothing that gives them any right to disable my ability to add that song to a playlist. Unless of course I am breaking my part of the agreement in the license or my ipod becomes obsolete. In this case, I am playing a legitimate version of the game, on an unmodified and still current Xbox console, with a legally purchased DLC specific to this game.
But to your question of contacting Deep Silver, I sent an email to them last night to question why the DLC was deactivated. Yet to hear back of course. It's early.