Same here, I've clipped the same guy teaming twice and uploaded it to Reddit. One was a month ago, and the other was a few days ago. He's still playing the game. But it is against the rules so I don't know what's going on.
Generally speaking, a report submitted to our team is not an instantaneous "this person will now be banned" transaction. I hand the report off to our team and they perform a routine inspection to verify allegations and then enforce per our code of conduct.
I've dropped a note that you've made repeat reports on a particular player, but that's the extent of the information I can share with you about this.
Ultimately, the goal of a report is to investigate and verify. The process is not often instantaneous and investigations can take time. The goal is to get it right.