The cdkey was used to cheat. Therefore it got banned... That's actually everything PBBans, as a private anti-cheat organisation, has to care about. If it would be unbanned so that you could use it, the dude from germany could use it to cheat again and get banned a second time. So... this will not happen.
Multiple people have explained it to you thouroughly. If you want to play again, buy a new game.
The End.