The banning system for trolling

Lets say that im playing Varus mid and leona goes support lux goes adc Leona goes midlane and says im not supporting adc lux and then follows me around all game taking cs xp and flaming now LEONA wont get banned but if lux says anything about she will get banned. Remember the tahmkench and Anivia trollers THEY DIDNT GET BANNED TILL RIOT A PERSON SAW THEM. In my opinion in reports it should show after and before match chat and then if someone that doesnt get the role goes to the lane they should get banned