Banned account for untrue reasons

Hi my name is alex, i was playing with my older borther on the United states realm of : "undermine"
Both me an my brother just began playing retail world of warcraft just a few days ago. Both me an my brother were farming gold at redrige mountain we were killing a form of mob that looked like river paw's but level 13-15 i think. while we were killing there (me on my lvl 17 hunter Snyperer)(my brother on his lvl 17 rogue Tuk) we came across a lvl 21 mage. i cant remember her name but she was getting annyoed that we were apparently taking her kills. an she told us to .... off an stop taking my kills. but we didint want to leave as we were both doing a quest ,then she started wispering (my brother (Tuk) to .... off an to get the .... out of here an that this is her spot an she started being racist calling him racist things. an all my brother did was reply to her ." go away" " Leave me alone" " get lost for god sake go level up some were else" "Grow up!" an than after she said .... off u stuipid australian peice of mother ....... crap" my brother then replyed to her . " thats what she said" then the mage said to him in exact words " IMA get u for that one!" then she logged off an then like 10 minutes later he recived a message from a GM saying your account has been temporarly suspended. my brother went to the site that the GM had linked to him. he went on the battle net site and it wouldent let him sighn in on the forums or battle net site. if i can please be told if there is a way to recive my bother account back as he is not sure what he was banned for an what to do to get his account back..... please can a helpful GM help my brother out.... ty