It's an automated message service- trunk line- can't be called back, form verizon for debt collection of verizon cell phones. Sometimes the message works right, sometimes it may not... but you have to wait a minute for it to kick in.
I have been receieving calls from this number for about 4 days straight, but i always seem to miss them. When I call the number back it says it's disconnected. I think it's Verizon as well but I am not sure why they would be calling me since my bill is up to date. it's highly annoying!