Harassment

There is a player on the game that's been harassing me, they kept sending me "advice" constantly until I blocked them and now they scout me all the time, attack me anytime my shield is gone, attack me when I'm harvesting, etc.
What can I do, I've told them to leave me alone but they won't this is rediculous, I know it's a game but this feels like an attack on me cause I didn't want to listen to their "advice" or join their clan.