Learn to screenshot in-game for evidence of trolling/toxicity

That way, you can make most of us in Boards to believe the experiences you have. Usually when a certain threader says he has intentional feeders, most of us would only assume they're just newbies at their champions, making it hard for us to believe if the feeding was intentional or not.

Seriously, just hit F12 on your keyboard to screenshot an image, and send it to Riot Support. That way, it'll make things easier for them to punish players accordingly.