Reporting cheaters on games like battlefield 4

I have a new friend that can't be killed by other players. He has the ability to lag out when fired at and it does not matter if he's in a tank, flying a chopper or just running around. In two months time I've only seen him kill him self by crashing a chopper or falling to his death. He also leaves the round at the end of every match. I've reported him about 100 times but nothing is ever done about it. Is it just a waste of time reporting people?