My friend account get blocked for no reason

Hello Blizzard.
Now i want to play HOTS with My friend but his acount just be blocked for 7 days and he don’t know the reason for that. In his mail said that from report for AFK, intentionally dying… but most of his recent matches he played with me and he said told me that he hasn’t done that recently. That is believable because when he received the warning email he admitted to me about AFK even though he also lamented the untrue mail. At least, most of the recent matches he played with me.
Hope you can do with that. Recently, he and I play Nova and Valeera and the couple are annoyed, so those reports probably come from angry players who lost.

His Battle Tag: ks75vl#1321

Thank you and sorry for my bad english.