In MMOs, bot bans tend to go out in waves.
Why?
When you find someone that's botting, the right answer is not to ban them right away.
It's to see how they're evading the bot-detection measures that are in place so that you can update the detection mechanisms.
Then, you use that detection mechanism and run it to see if it catches them. If it does, then you also make sure that it's not picking up people that aren't botting, because you don't want to ban someone that doesn't deserve it. If it meets those criteria, then you implement it and it bans everyone using that bot. If it doesn't, then you go back to the drawing board and try again.
In other words, be patient. Banning bots one at a time is not merely inefficient, but actually counterproductive, as it can tip off botmakers that there's another ban wave coming, giving them an opportunity to unload all of the resources that they've harvested before the accounts that they're stored on are banned and locked.