Detach CD key battle net

[mathewpn]

Hi guys ,
I would like to detach/remove my Diablo III CE edition CD key . I know , This is possible because in EU is allowed to sell software ( secondhand ofc. ) . I wrote this to ticket and GM told me to write to legal department of blizzard just post mail to France , no chance to email .... Like in the 19th century :/ Is any way how to detach CD key , without spending time ... In which cases are they able to detach CD key ? I have done this already but with WoW ... I´m not going tu sue with them ofc. , but I really hate this company ... Ofc. ignoring twitter , mails from me , etc.

Why ? Just want to sell this game

Cheers