Recvd' call from this number, didn't answer, no mess. left. Caller ID said Unknown Name

I answered and they hung up.

Dead air call, left dead air voice mail even though I answered on the second ring.  Reverse lookup shows this to be a land line in Bayonne, NJ just south of Jersey City and part of the NYC metro area.

This may be a data collection call by a bot to determine valid phone numbers with VM for use by scam callers who want to bypass the DNC list.

I think they are just trying to see if the number is a working, valid phone number.

So, I have not answered any of their 30-something (to date) calls.

That's right, over 30 calls in less than one month.

I have been receiving calls from this number for a long time.  I finally decided to answer.  A woman told me that there was an insert in my June Atlantic City Electric bill and then the call got disconnected at her end.  I tried to call back, however, I received the message that the number is not in service.