So i got my phone back today. I think that its a new one, my old one had cracks in the plastic border, scratches on the back and on the glas. But this one has none of that! They said they did a boardswap but they actually replaced everything! It took them 2 days (!) to repair my phone. And the best thing of all is that i didnt have to pay anything.
But no rooting for me anymore, this time I was extremely lucky but i learned my lesson.