How can I get him to stay away?

He doesn’t want anything serious, just wants to hook up. blocking isn’t working, he finds ways to keep contacting me. (friends with benefits situation for two years) I tried ending things (communication) he keeps coming back. We’ve both came to the conclusion that we want diff things but he doesn’t stop popping up and trying to come back. I’ve told him several times to leave me alone. He won’t respect the fact that I am no longer interested in being a friends with benefits.
How can I get him to stay away?
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