it call and when I pick up , it did  not speak and hang up

Same miserable old scammers with a new number.  You block one, they come right back with another one.  It never ends.  Aggravating morons, the lot of them.

Calls several times a day--usually every day or every other day. We never pick up. They never leave msg. We get so many robo calls that we never answer the phone unless caller i.d. is someone we know. Can't fight the robo. If you block the number, another one will come along to take it's place. Shrug it off.

i wish someone would put a stop to these robo calls!

Pasadena is right--robo calls will not stop, so make them less annoying. I have a Panasonic system that can block 250 numbers, and I have all phones set on Silent mode.  The recorder comes on if a message is left (most telemarketers don't) and I can answer the call then--or later when I return.  I block the few telemarketers that leave messages, and delete numbers from CID when convenient.  A call with a ring that isn't heard is much easier to tolerate.