This is happening to me. They call on a daily basis pretending to be Verizon and ask for my zip code or to pay my outstanding balance of 500$ over the phone. THIS IS A SCAM. Another number they call from: (415) 592-5355. You should click on the contact and scroll to the bottom to select "Block this Caller"
Called, hangs up. Not sure about getting charged by calling the number back, but it asks if I am Lissa or (Alyssa) Hill and then to enter my 4 digit zip code. Seems pretty scammy to me. Maybe verizon should shut it down.