How to have chat appear in downloaded games?

I downloaded a match to try and get some1 punished for denying to co-operate but I reviewed the video and chats do not appear? I have the match downloaded still , is there any way to make chat show up so I can send it to riot to have them evaluate it and hopefully ban the person? After-game lobby some people immediately left so they probably didn't report and the others who stayed and listened to me asking to report the person said "My main got banned before, It felt really bad so I don't want to report him"