I think it's a credit card scam -- been going on for years but Verizon (who is their provider) won't do anything about it. Verizon is 100% complicit in this so if you'd like it to stop, report them to the government. OR, order the service and photograph the people who show up.

I received a call from the 310-487-598 telephone number this morning. Nobody responded on the other end so I hung up. I'm also on the do not call list. It's very annoying...isn't there something we can do about it?

no message.  incomplete number here too. [***]!

Got a call from this number today. Didn't answer. No message.

no one was on other end.