After quick playing i joined a server with a 2v0 situation and after joining i noticed every bomb planted and went to work. Soon after the enemies complained i should leave them alone they dont want to play they just want to get some exp. The problem is that i dont know if i should openly spill out evidence and names or if i should contact the support. I feel like it isnt a thing people should do.
People openly farming on empty server.
Report them to the support. People shouldn’t do this and according to a trustworthy source they get punished for farming EXP.
Well, xp gives you nothing in this game, so, I guess, if they want to waste their time like this, it’s their problem. But, from the other hand, we are doing our missions in a legitimate way, so yeah, that feels like cheating. Not that I care, though.
Contact the support. Openly naming and shaming is not allowed.
I sometimes stick in the same server after the previous map because I’m getting tired of searching for new servers just to end in my face after I join them. And most of the times when I stay in the loby I end up playing vs 1 or 2 guys just playing regularly waiting for more ppl to join. Your example on the other hand is clearly an abuse. They even politely told you to leave them to farm 
Feel free to report them to support!
This isn’t allowed, much like the old exp exploits.