Calld me n the caller stood on the line for about 11 sec n click

Got a BS call from this number 1 (831) 291-9709.  As usual no message left to protect their self, also numbers that begin with a 1 then the number are known as "Cloaked" as to hide the identity of the caller.  I block these numbers yet they call back from another cloaked number and never leave a message but they hold the line for a few minutes & then hang up.

Because I did not recognize the number, I did not answer.  No message was left.

called at 1122 hours EST - no one on the line, then call disconnected

How I wish for them an itch they cannot reach for some time;