Blizzard ban policy

Do they have some kind of ban policy for using AFK bots ( something like pirox bot ).

Do they first ban you for like 72h or is it possible to get perm ban when they caught you for the first time ?

Also is it possible that they ban you like few weeks latter or a month(s) latter ?

Thanks in advance =)

They can ban you:

When they want,
As long they like,

if you run some 3rd partytool like an afk bot