Getting hard trolled by an autofilled malz main. Why wont they get banned?

I just barely got out of a ranked game (g2 Promos by the way, which I failed due to this). I queued for mid / jg and got mid. The dude begs for mid and i politely decline as it's my best role. Says "positive things in chat" With them obviously being anti ban fodder (Good luck team we got this!!! kinda stuff) He takes smite anivia support, maxes w and takes minion demat, Smites the blue buff from our nocturne and cannons from our adc and myself, traps our adc into a 2v1 from the tower constantly, roams around taking camps from nocturne and farm from me. Had tons of "positive messages" Macros. Then rushes zzrot tear and mobis. Refuses to listen to our polite pleas for them to leave our lanes and camps alone, Now me playing Twisted fate i needed to ult around to try and recover the game, which she'd then w and cancel my ults as well as tp summoner. She DIDNT INT THOUGH. which is why she probably wont be banned, Meanwhile the entire game preachinga bout how im bad at mid even though she threw my lane. She constantly walled people off in fights and got them killed, and just griefed the entire game, as well as refusing to ff at 15 because yeah :T It disgusts me that she wont be banned or anything even though it's apparent and very toxic just because i didnt wanna give my role away, Why do people like this get away??? [zombie-brand-mindblown]