So, honestly, that doesn't even sound reportable. They aren't AFK (since they talked to you) they aren't even all that far out of the level bounds of the hunting area it sounds.
If it's genuinely impacting your game play, the mechanic would be policy report but the GMs aren't going to tell us what they do with those, it would be like the IRS telling people how they catch tax cheats. Also keep in mind, abuse of this function will get you in trouble.
As a suggestion (and I know, as the aggrieved party you shouldn't be the one who has to change, but such is life) there are a lot of 30ish hunting grounds, consider finding another one.