What would you do in this situation?

A car would come in front of my house at 3AM and come in and out of my driveway. This happened for 3 years. I finally contacted the police, but they were unable to locate the vehicle. It continued ti happen after I called the police. I believe that the same person responsible for this has left 125 haring crank calls on my voicemail, my mom's voicemail, and my parents' landline for a period of 5 years. I know he is tapping my line because my mom's cell phone is an unlisted number and I never told it to him. He leaves messages with disturbing sounds on my voicemail. I contacted the phone company, but they told me to contact my attorney general. He calls from an unknown number. How do I stop this?