There are flaws within the Blizzard bot detection system. And Blizzards approach of bot detection and Zero-Strike approach - without refunds is at least shady, because of potential privacy and legal concerns.
For instance a few hours old accounts getting banned permanently.
Accounts which never had a bot tied to some getting banned, because friend list and/or on same ip are botting accounts.
There have been and there still are hacked accounts, which might have been used to bot.
Also there is a rumor that people have been successfully hacked into the Blizzard system and unbanned accounts manually.
Because of the chaotic situation with Blizzards approach to banning thousands of accounts, an appeal is always an option. Many report success with an appeal.
Good Luck