What seems weird is it does not sound like she ever tried to actually confront him. Block after block, but not really confronting him. It seems she didn't want to hurt his feelings. But waited until police action? That seems like a terrible approach.
The most confrontational she got was "I caved and sent him a message asking him to please stop messaging me so much or I’d block him." How surprising that didn't work.
You need to be more confrontational in a situation like this - either a heart to heart approach where you lay it on them, or something more aggressive. Blocking for the umpteenth time is not going to work.
You could call this critique victim blaming, but the my intent to encourage people to handle the situation better, without someone repeating her mistakes.