Yea, this is one of the few areas that actually does apply for FC to step in and moderate. Report it or contact a community manager with the server info and screenshots.
There are instructions in this post, although note that unless you have screenshots or ‘indisputable proof’ they can’t be bothered. And they only may help. No guarantee.
https://forums.funcom.com/t/harassment-and-griefing-issues/15950?u=maedhros