Click the bots name in world chat then click "Add to Blacklist".

He is using pms.

the one on my sv used pm's till one day he used world chat but still theres nothing you guy can do about them?

and don't use the "report them to custom" thing a lot of ppl did it,including me and got the clasic robot answear

Just ignore the messages. That's the best we can do. I dont open the messages. Since I know the name of the three bots in my server and all of them come together., i just press ignore near the view *on and move on. But the counter measures are slow for sure as mentioned above. Atleast a regular update on what is being done, if shared with players would be a relief.