Who called from 7604076572

Received hang up in voicemail.  Number blocked.

Received call and noone said anything, also received a call from a similar number 760-407-6563 earlier the same day with the same action.

I receive a call from this number on a daily basis. When I answer all I hear is a click and then silence.
Almost sounds like some one is either trying to record something OR charging something to my phone.

I don't answer anymore I just let the call go to my voicemail. When the voicemail picks up all I get is a busy signal in the voicemail recording. VERY suspicious and annoying!!!!!!!