Actualy i haven't used any Hacks or exploits
It is actualy illigal not to give people what they pay for, unless you get canned for not sticking to the rules...
Yes i do feel sorry for you that you have lost your account.
But basicly having a trojan on your system tells me that you have been dodeling with something you shouldn't or that your firewall is not effective enough, or you do not scan your computer frequently enough(considering you have a firewall other the windows firewall

).
Blizzard can not be made responsive of an account being hacked, cuz their password system, is as safe as it gets without having the user use his fingerprint. A Key-logger can and will get your account banned, thats the sad trueth. And maybe you are lucky that blizzard will trust you maybe not.
A hint from me is... Please DO take virus checking seriusly. There is nothing worse then losing an account you have played on for 2 years.
I use a password coded notepad item and then copy the code to wow and other programs from there, the Keylogger (if there is any) will not be able to get to the codes in my notepad item and he will not get his hands on it unless he hackes directly into my computer, and takes control of it.
Hope i didnt scare you to much. :=)