How to report a user who violated Code of Conduct?

Hello. I really need to report a user who violated the rules and should get banned. He sold his Battlenet account to a person and even recovered it. I dont have it on my friend list or recent games, so i cant report it in-game. Is there any other way to report this? I searched up the support categories and didnt find anything close to this type of situation.

For extreme cases when there is no option to send a report in-game there is always the alternative of sending an eMail to

PS: Just remember that not only selling an account is a violation but buying one, too!

Tysm, i saw this email but thought its not okay to use it for this situation. Yes, i know that purchasing is also violation and i have no idea who is buyer. The person directly told me abt this without thinking about the consequences i guess.