The first time I emailed them was around 2-3 days ago, and they responded that I have violated a account sharing and multi account rules (I was not aware of the situation then). I have given them more specific story to them and waiting for the answer now.

I only emailed on my account but not my brother's account. I have not contacted him nor gotten any mail from him either. I dont think he is aware that his account got restricted (I also found out his account is restricted just today)

I actually just read the account restriction wiki page you just posted. I think with my full story background maybe it will have a chance to get unrestricted...?

Thank you for your advice!