To report someone in the same district for verbal abuse, use the /report feature. Say "Player X" is being a bad boy. Simply type /report Player X and select "verbal abuse" on the screen that pops up. That's all there is to it.
If you're not in the same location, take screenshots and report them through support. (you can find links to support on
www.guildwars.com)
If your account was banned/suspended, you can plead your case with support. But don't expect to get your suspension/ban lifted if you were misbehaving (using profanity, etc.)