Best/safest/surest way to raise behavior score

I've been placed in really bad matches for the past 20-30 games. If I want to be a team player, my team lets me die, then maybe they swoop in for kills, and I get behavior reported. I am doing my good builds, like euls on support, bkb on carry.

I do not ping. I do not talk. I do not use voice. I am muting the toxic people, who abuse chants/ all chat / "ez" idiotic replies.

How do I get back to 12k behavior score? Thanks!