Telling people to stop being toxic is verbal abuse?

Every couple of days if I see a teammate being toxic to me or towards anyone else I will say something about it before that teammate goes afk (they always do). But when I say something as simple as "Stop being toxic" I get a notification at the end of the game saying stop doing verbal abuse. I got banned for 2 weeks back then and Im really trying to avoid being banned again. Should I just mute everyone in my game? Seems like the only option at this point. Anything is reportable nowadays and League of legends has been more full of toxics, afks and other things then I ever seen. I fail to see whats wrong with telling a teammates to do something or telling them to stop being toxic.