You have to select an option of what your feedback is at the bottom then type your issue in the box under it. It's on the bottom right. If you have that video and whatnot you should include that you have that if they need to see it.
In addition never expect immediate results. They need to build a pattern/case against someone before they can ban. Sometimes it's just a fluke. They need to establish a person is actually cheating.
lol I had a team mate that thought I was the enemy. He was able to hit me and make me bounce around the place but luckily he couldnt take any damage from me. It was quite annoying cuz when I see him he went and attacked me, I was kinda having fun with it though lol. Wierd thing is, he saw me kill the other team, change the nodes to green, and other stuff and he still didnt notice he was attacking his own team mate unless if he was trolling lol.