Question regarding how to handle people who use bot/script clients..

I just played a game against a Sion who admitted to using a "Bot of Legends" exploit in which he had an usually high amount of mobility during his ult.. Once the game was over and it was time to report him I realized there was not an option for cheating or hacking on the list of reports.

So here is my question: What is the appropriate way to report cheaters to best ensure that they receive justice? This was an incredibly unfair hack that gave him a significant advantage over our team.

Here is a link to the script he admitted to using as well as a link to another forum post my friend made. Thanks in advance for your responses. http://botoflegends.com/forum/topic/39140-exploit-sions-ultimate-control/ http://boards.na.leagueoflegends.com/en/c/bug-report/aybuzFwe-player-openly-admitted-to-cheating