You were banned for spamming "Heil einstein" in chat, which is not acceptable for obvious reasons. In fact the day before you were banned; you were warned, kicked and finally muted for doing this. Furthermore you were told that continueing your einsteingruß-spree will get you banned for an undetermined amount of time. Obviously unimpressed you kept doing this shit the next day and got your well-deserved ban.
Unban is possible if you can assure that you'll stay away from using that kind of language in the future.