Okay I'am back, here are the results.So first I logged out my FB application and used another account and logged in.
Started jurassic park aaaaaand.... It didnt work. ???? BUT I went to settings -> Facebook and deleted my FB account there. I logged on with other account opened jurassic world and TA-DA new game started. So I was excited it worked but when I logged back on My account in settings (and application) my game was gone????????, at that moment I cried. After 9 minutes of crying I pulled myself back together went to settings (INgame) and there was an option "Logout from Facebook" when I pushed it my app closed and it said, login with FB or as visitor. I clicked FB and everything was back to normal ! Phew ????????
(This worked for Subway Surfer to) so it will for every FB-connected game I assume. But logging out from your FB application does not affect your game you have to delete your current active FB in phone settings before any changes will appear ????????
This is cleared ???????? I hope it can help some other people on the forum to ????
Cheers and thanks for the help !