OK that info wasn't clear in your former posts. But ... wouldn't it have been more simple to just ask their
support about your account? Did you contact them in the menatime? Did they confirm the erasure?

I couldn't find a way to contact them directly on their a website and I didn't want to post in a German forum in English unless I was desperate. I emailed them about it after colorito gave me their support email address in this thread. So far I haven't received a response.

Then we got to wait and see what they have to say. I think you are probably right and they deleted your acoount due to inactivity. But that seems to be a common practice. My non-used accounts at game.com, selgros, gamesrepublic, games-mart etc. were just gone one day.

What I find more annoying is when a store has deleted a game from your account without telling you. Silagames for instance has just taken away the DRM-fee version of Secret Files Tunguska from my account since they offer only Steam keys of it. When I contacted them ranting about the issue, they replied: Take the liberty to buy a steam key instead. (What I didn't do of course.)