Well on my first account (old account) took ages to get banned (like 5 months- botted some 99's) (this was 6 months ago).
Now i created an account 3 days ago and botted not very much (watching most of the time btw)- use auto fighter sripts and i got perm banned already. I've added a few people i thought were bots coz they got stuck on doors etc and they have all be perm banned already! Srly though- in total i must have botted about less than 12 hours on this account.
....Perhaps if u have already been banned in the past- they closely monitor you. Anyway, if i had to play this game again... i'll have to play for real heh . Thankgod i got banned on the free trial (was gonna pay for this game after haha).
Anyway, if want evidence of how successful they are are banning people now... if u see a player who gets stuck and they are obv they are a bot- add them to ur friends list and keep checking their highscores... if they are removed from highscores- they are perm banned.