this is the order of shit i would do (if the bribing thing actually happened)
1) escalate the issue - bring it up to the org owner, the coach, literally even riot to investigate it and get consequences
2) if that fails then i would at least approach the guy privately first to hash it out and get an apology
3) if that fails i would make a serious public statement asap exposing the situation and warning others about the player with receipts
i have no idea what goes on in your brain to instead hold this shit for almost a year and drop it the second they lose a match