The best place to start is
How to report Problematic Players. Understand that if you are on Teamspeak, you can generally find admins there who can quickly take care of your issue. If no admin is available on teamspeak (Extremely rare where none is available) then PM an admin about your issue. Include what time it happened, what map, who (If you know) and what happened. Trust that we will take care of it, even though it may not fix the problem immediately. We do scour Battlefield Recorder and Chat around reported events.
Lucky Shot