Caller ID indicated FRNK MAIN CA.  No idea who what this is - blocked without answering.  I assume it's a Medicare fraudster using a new number (I get 8 to 10 of these medicare calls a day) or, from other sites, a number used by the 'let me on your computer to fix it' gang.

Call on 6/1/2017 510-513-4214 CallerID=Frnk Main  CA   No message when don't answer and I will not ever answer even tho this is a local area code.  I get about 10 of these scam calls (Medicare, Healthcare, paincare, etc.) a week and they change their number and their story on a daily basis.

Scammers

"Medicare Help Center" seems to be the nick used by this DNC Registry violator. Looks like your Caller ID may have displayed some of the scammer's carrier data "FRNK MAIN CA"; as in ... "Ported to Local Access Services LLC - CA in Frnk Main CA on May 22nd, 2017" The calling center operator disclosed the name "Medicare Help Center" when receiving an anonymous return call.