Ok to keep you informed: Unluckily, things couldn't be sorted out. I tried to explain them my situation and they reacted by freezing my account until I can verify them my identity by filling out a form, which includes lots of personal data. As I'm not willing to give the out all those infos (Copy of my ID-card, 4 first and 6 last digits of my credit card, copy of electric bill etc.) they wont refund my account balance. I asked them to just keep the status before I confrontated them with my issue but now they won't reactivate my account until I verify my identity.
It ended up in lot's of e-mail correspondence and everytime I got a standard answer, which was always targetted at my brother's name, even though I explained them many times who I am and what my problem is. They still think it's my brother who they are dealing with. So probably I would have to prove them my brother's identity.
Due to many forum reportings, asking for filling out this form is a routine practice of pokerstars. But they can get very ridiculous there, like asking for more and more infos: http://forumserver.twoplustwo.com/28/internet-poker/pokerstars-frozen-my-account-20-days-already-standard-security-check-1226644
In the end, its my own fault, I didn't recognize, that 4 years ago I registered by my brother's name (without any evil thoughts), because he also was the one that could borrow me his credit card. That was not very smart, I admit. I probably broke their T&C's by doing this.
So I gave up my hope now to get things fixed, as I don't feel like givin them all the infos they want. There would actually be easier ways to verify, that I am the one who mailed them and also holds the pokerstars account Im claiming.
Luckily I always cashed out bigger winnings, so right now I will "only" lose 100 dollars and won't be able to poker in future. that sucks but I guess that's what happens when you get yourself into a online poker gaming, where there's always the other side with the whip hand.
Greetings
AustinP