His ex won’t stay away?

I’ve posted about this before but essentially they dated for a couple years but have been broken up for a year a half.

She has always claimed that he cheated on her with me and i ruined their relationship but it’s absurd and there’s no way it’s true.

Anyway, she won’t stop messaging him. He blocks her on Facebook and everyday there is a new number from a texting app texting him. It’s making me crazy, she’s always there and she’s all I can think about in the craziest way, like it makes me so angry.

I know it’s not his fault but it makes me angry at him. I’ve tried messaging her nicely, nothing. At this point a rude message is warranted, right?

I literally had a dream about her last night because she is ALWAYS there, texting him all hours of the day about how much she misses him etc etc