Hi. You may want to do a combination of call block and anonymous call rejection. And even call intercept if its available in your area.
Here are some of the features you can use. Just sign in at
www.myverizon.com and look at your account you can add features there or call verizon and ask to add these. 800-VERIZON
www22.verizon.com/residentialhelp/phone/calling+features/using+calling+features/using+calling+features.htm