I just noticed I had a "missed call" from them. I have an app that hangs up on people not in my contact list.

Phone rang they did not leave a message.  I've gotten several calls in the past few weeks with California or Idaho area codes.  Maybe it is phone number spoofing.  I ignore numbers I don't recognize.  A legitimate phone caller would leave a voice mail.

spammer

I got a call from them a couple months ago. I missed the call and took no thought into it. Then I got a call from them a week ago. I answered and said hello, but they didn't respond. I think I could barely hear something but I don't know what. I texted them and got no response. A couple minutes ago, my mother left her phone home and got a call. I looked at the phone and it was the same number. I called them back but it said that the number was out of service.

Just received a call from this number not even 5 minutes ago. I didn't answer- I never do if I don't recognize the number. They are now blocked.