It doesn't show that you own the game, did you return it?

Erm, no? I was not even thinking about returning it. I like the game, because I spend 11 years of my life in GDR (DDR)....I am kind of simulating my past with this game. Additionally, the game is marked as installed in my game list here....what went wrong?

Ps: There is even a message next to the game, that I purchased it at june the 29 and played it for the first time at june the 30.

There is not a play game button? or install button?
If game is installed.. you could try browse local files
https://gtm.steamproxy.vip/sharedfiles/filedetails/?id=760447682
.. and run SETUP APPLICATION.exe or SOVIET.exe or SOVIET64.exe?
Maybe you get some error message?

Ok, I checked everything. The game is colored white in the game list(aka installed), but the "purchase" button shows up right. Additionally, the game is installed on my harddrive, but when I press soviet64.exe, it says "can´t initialize Steam".

So, the problem must be on steam´side.....I bought the game, but steam seems to tread it like I did not, despite the game being installed on my harddrive.

OK.. from what I see.. you should check if you purchased for same user.. as current user signed in the steam client..

I will contact steam. I have only one account in steam and if I would have purchased the game for some other user, I would never had the chance to install, isn´t it? But I have it installed. I faintly remember having the same case already. Game bought and paid, but steam counts it as "not bought"...

I found the problem. Steam has refunded the game without my knowledge. O_o