As is confirmed by a Support Forum agent in another thread, cheating reports via right-click report and hacks@blizzard.com are handled by the same team:
Hackers, cheaters, and botters are not banned immediately. It does take time for the team to investigate, learn how to break the bot they are using, and apply the ban wave. It is not instant.
Also keep in mind, a lot of these criminals (yes, they are criminals) will use stolen accounts. They will keep deleting characters and will start new ones in an attempt to avoid detection.