if they do the mex bullshit explain to the how mexes work. if they ignore, rec the nano.
if they rec shit that is being rez'd or eat rec, Tell them in the most obvious manner that they are being a dick - without attacking them as a person. maybe...
say "Hey dude the front line is collapsing we need your help"
say "[whatever they are building] can't save us if our front dies"
place marker "I need that rec to cover your ass"
Once and they ignore it, maybe they didn't get the memo. repeat the message with much stronger words.
they ignore it twice, repeat the message with the strongest words you have and warn them of consequences(!kick) for not playing in a way that supports others
three times and they still ignore. point out the problem to your team with markers and !kick.
if they respond with an argument that is valid, acknowledge that.
if they respond with a bad argument. point out it's flaws and reinstate your point (shouldn't count as an ignore)
if they respond with a shit argument(e.g. i want my award!/ur a pro) then it should count as an ignore but still point out that that argument is troll stuff.