First of all, watch your language,
Second of all, you have no clue what is going on when it comes to raiding with other guilds etc, so if you are clueless about something then stay quiet about it, otherwise you will just get proven wrong. (I wont go off topic to waste my time on that)
Milan has logged you acc and he has went on your horde characters and he has chatted with Locos, then after that, you said the same thing, that he has access to your account.
We do not know if he has shared the account with someone else or what not, therefore we can't help you with this issue.
We are not responsible to what happens afterwards you share your account with someone.
There were similar cases, http://forum.pandawow.ru/showthread.php?t=190152&page=3
Also, i have said this in the past, people don't actually "HACK" on private servers.
You have either shared your account with someone and then afterwards you got scammed,
"Hackers" wont waste their time scamming people on the Private servers, because they don't get any profit from it and they just waste their time.
And even if they did "Hack" people, they certainly wouldn't target random members, they would have went for someone who's "rich" and has valuable characters.
Or they would have went for higher up members such as staffs to try to use the permissions / privileges in their advantage.
Therefore i doubt that we can help you with your current issue.