Guy won’t leave me alone

It’s been 2 weeks since I gave a guy my number just so he would leave me alone because he seemed dangerous in person. I blocked his number as soon as I got to my car & since then he’s texted me from over 15 different phone numbers. I told him to stop texting me multiple times. And I’ve told him no to all his advances. Why should I have to change my number because some weird man won’t leave me alone? Is there anything I can do?