I don't really think this counts under serious harassment. It IS a PvP area - PvPers should be expected, and there are a lot of people who take PvP seriously and wouldn't stop even if you said that you didn't want to be killed. If you're getting verbal harassment as well, maybe you should report.
Also, if there were complaints from others or posts on the official forums about harassment from the same person/people, you could also try reporting~ o-o