stopping unwanted private messages

Level 7
When I'm in this area I see that I have private messages in my in box, they are all from a crazy person that I have asked repeatedly to stop sending and finally have quit asking but it seems the less I care the more they keep getting mad to a point now where the messages are simply inappropriate and can't even be shown here for an example. I see that there's a link that says "ignored" but I can't figure out how to place that persons is in that area. I can't report them from that area to have it stopped and I'm not sure if I can even block them and if I did will it stop these private messages and how do I do it step by step. I've tried and found no way to do it.
Level 9
Well, I’ll admit that I’m who you’re talking about. We have both publicly and privately beat each other up. I also complained about you😂. I’m not gonna argue with you anymore. I am sorry for being rude....