Read the boxed text.
This should be banned asap.
You should have included the game link.
It is hard to understand what you complained since you just pasted the image without much explanation.
And the title is "pusher detected", rather than "alt detected", so it looks like you complained about the players being rude and pushy.
Purple and yellow are in the same team. But purple betrayed his team and asked the enemy to attack yellow. Even if we exclude the alt issue, he is playing against his team. It is punishable for this reason alone.
Two breaches of rules:
Playing with an alt in the same game (cheating)
Purple playing against his team
Have you reported them yet? You should explain clearly in your report.