Japanese by Example
Learning through examples in manga

Nothing to do with Ayumu's situation with 知ったことか

Grammar Explanation: Lack of interest with 知ったことか

Manga panel from それでも歩は寄せてくる showing example of Nothing to do with Ayumu's situation with 知ったことか.
それでも歩は寄せてくる » Volume 2 » Page 97

Sakurako tells Takeru not to go to the shogi club as he’ll get in the way of Ayumu being with Urushi. However, as a new member of shogi club, and as a man, Takeru feels it’s his duty to show up.

タケル:
「歩(あゆむ)の事情(じじょう)など知(し)ったことか」
“This has nothing to do with Ayumu's situation.”