The caller, Cell PHONE CA ( displayed as ID on our phone ) called us  with 310-328-8215  @ 09:36 A.M.. I was out of  Country. Iy left no message. I returned the call hiding our number on p1.3.20`16. I heard a message: " Sorry, the mail box is full."

An unwanted call from this Santa Monica cell number arrived today.  When the call rolled to voice mail, the caller left no message, just dead space.  This is typical of robocallers who use automated dialers to place calls.  If a live person answers, the dialer transfers the call to a live, illegal telemarketer.  Slick, eh?  I always let the answering machine take calls from unfamiliar numbers.

This number calls repeatedly and abandons call each time.

This caller is a telemarketer selling home improvements and remodeling services via HERO Program. HERO does not have contractors in my area (Camarillo).

exactly the same here...has happened many times so no number is blocked.