Who called from 5309035687

Called my work number at 12:44am. Left no message in voicemail. Looks like an automated call system.

Got the call from 530-903-5687 at 2:30 am and when I called back in the morning I found this is bad number.

Calls nearly every night at 3:00 in the morning. Leaves no message. How do I stop this?

Received a call at 2:15 am ..when I called back..the recording said that phone was not in service.
I use Ringcentral for my 800 service and I will be canceling my this number tomorrow..

called my 800 number at 6:57 Am with blank message.  When I called back phone was not in service.