I answered finally because the calls were getting obnoxious. Some thick-accented person said he was from Verizon, the said he was from AT&T midway through his "talk." Then he was heavy breathing on the phone. WEIRD!
A man called me this morning from this number. He claimed to be affiliated to Verizon financial dept and asking me to pay a Verizon bill which I had already paid. These people called me last week via 312 324 0869 asking for payment of the same bill. Obviously they are connected to someone inside Verizon. Very dangerious!