Need advice

My boyfriend and I have been together for almost 4 years now with a 1 year old daughter and there is this girl that I don’t like named Dionne that keeps calling and texting his phone constantly. I’ve asked her to stop and I told him not to contact her anymore but she continues to call him. She says that she is just calling and texting him to make me angry and I don’t know what to do about it. He stoped calling and texting her when I asked but she continued to call him. What should I do?