How can I get rid of my super clingy ex bf?

This guy I met a couple months ago and dated won't stop texting and calling me. I moved two hours away to try to work things out with my high school sweetheart and my ex knows that but he wont leave me alone. The bf I moved for has even asked him to leave me alone but he won't. What can I do to end things amicably but so my sweetheart and I get some peace?