It is a bit complicated, Coldpaws, as there is often a misunderstand of what is considered griefing or what is zone disruption and what a lot of folks actually got in trouble for.
Repeatedly killing quest givers, generally isn’t a violation of policy. If the mob can be killed, we generally do not penalize someone for killing it. There are situations in which we may intervene, but they tend to be rare and extremely conditional.
Corpse camping or otherwise participating in PvP, regardless of the level disparity, is still just PvP and we have no policies against it. If someone is flagged for PvP, in War Mode, etc… they are free game.
It should be fairly straight forward, though it can be a bit confusing at times. You’d select the Support in the upper right corner of the site, then Contact Support > World of Warcraft > “I would rather categorize the issue”, > In-game issues > Report Player > Zone Disruption