I bought the game but the launcher says play DEMO!

So, i bought the game and wanted to play with my friends ,so i launched the game launcher and it just said play demo. i deledet the game and download it again, but the same thing happend Again.
i asked my friend but he had never something like that, so i concact you
to help me please Because i dont want buy a game and can't play it
"answere so fast as you can please i need help :I "
if my English is wrog/Not good enough to understand then i'm sorry
i'm From germany 13 Years old
Your XD_GAMER_YT