account banned

hey GM.
My account was banned a few days ago. I just reached lv60. therefore, its time for me to buy Epic Mount. I heard my friend say that we will banned account if we directly trade, so we go throug AH in game. Anyway, for some reason my account got banned. I told my friend I will pay back gold as soon as I got gold. I swear I did not buy any gold from outside sellers! so please lift my account, double check it. Thank you!
account name:Dugu
classs: mage
My account was banned a few days ago. I just reached lv60. therefore, its time for me to buy Epic Mount. I heard my friend say that we will banned account if we directly trade, so we go throug AH in game. Anyway, for some reason my account got banned. I told my friend I will pay back gold as soon as I got gold. I swear I did not buy any gold from outside sellers! so please lift my account, double check it. Thank you!
account name:Dugu
classs: mage