Moderators: You might want to shift this to the Germany forum!
From what I read I do not even know whether the OP's father was German. Being born in Germany (OT: Breslau was not only German "for quite a long time" but founded as a German city in the 13th century and this part of Silesia was under Prussian or Austrian rule ever since) does not automatically give you the right to German citiizenship.
The OP needs to know whether his father's parents acually were/are German and whether he was born as a child to German parents. If his father applied for a different citizenship he lost in German citizenship. Everything is pretty much complicated as Germany avoids dual citizenship. For details pls contact the relevant law:
http://www.bundesrecht.juris.de/bund...tag/gesamt.pdf
or more appropriate the German embassy.