Me and my friends ran into a 5 stack a few weeks back who had a cheater in their group. At first, the cheater was trying to be lowkey and clutching rounds after his friends died but after we started calling him out, he just started smoking himself and shooting us through smokes. We kept reporting him but no ban was issued. Upon checking the tracker data it looks like they have done it more than once. Red being the cheater and yellow being the people he usually queues with.

I've already sent a ticket to Riot with all these data but no bans were issued and the people he queues with haven't been banned either. The tracker data still shows that they are still continuing to play. However, I didn't check if they are still queuing with the cheater.