After looking into this I can see that you were banned for offensive language. I have posted the section of the chat rules that apply to this below. If you require a transcript of that chat please contact support.
5. Offensive chatting
Messages of an offensive nature are not allowed.
This includes, but is not limited to:
-Using vulgar, profane, or sexually explicit language or abbreviations of such
-Using race, religion, sexual orientation, culture, ethnicity, handicap, nationality, or gender as a means of insult
-Using sexual preference terms as a term of insult in any way, shape, or form
-Using threatening, harassing, defamatory, hate-speech, or libelous language
-Providing or requesting links to or material from pornographic, obscene, or hate-speech web sites
-Providing links to web sites with potentially offensive content without a clear warning
-Descriptions or details about any sexual act or sexual organs
-Using three or four letter acronyms that represent bad language will attract a ban just as if you had said the words.
-Using *,#,@ or any other combination of numbers or symbols in a word to disguise it or push it past the filter will represent bad language and will attract a ban just as if you had said the words.