POSSIBLE SCAM!  This is an alleged Verizon bill collection contractor.  It is ok to ignore/block them, If you block or ignore them nothing happens.  I am the account holder for my Verizon account.  They have never called me.  They have only called on my girlfriends cell phone, and sometimes on our house phone.  I have always ignored them, because Verizon uses text messaging to notify their customers, and nothing has ever happened.  I don't do anything until I get a text message from Verizon.  They obviously do not know who owns the account, all they have are phone numbers.  This is possibly a scam, I do not know that for sure, but I would be VERY cautious if you choose to deal with them.