I tried calling them during the business day. Same result: straight to voicemail (same message as off hours). This makes it more likely that this is a SCAM.
Have received multiple calls from 818-280-4644, caller ID "NORTHRIDGE". Not recognizing the number and not knowing anyone in that area code, I let my answering machine pick up the line, but the caller never leaves a message.
Caller ID says "NORTHRIDGE". They leave no message. They call three times in one day. The 818 area code includes Northridge, CA.
I call back after hours (using *67 to block my number). I hear the following, "Record your message after the tone. When you are finished, press the pound key."
The spoofed caller ID and the failure to identify themselves on their answering machine make me strongly suspect this is a SCAM.
I looked at other phone sites. One suggested a faux debt collector (they wanted you to pay a doctor's bill, but couldn't provide the doctor's name).