Report the calls to the Do Not Call Registry .....
Really

1call 6:15 pm.  No message. Seagoville, TX. Don't know who this.

Called, answered. Brief pause, click. No idea who this is.

Caller ID says:  American Alarm. Have received 3 calls in the last several days. They don't leave a message on voice mail.  They call at various times, morning, afternoon, evening. I'm on the National Do Not Call list (which is a joke, IMO). Unless these companies are fined when they are turned in and it hurts them in the pocketbook, they will continue to call, if you're on a DNC list or not!

Received a call from this number at 1pm - they didn't leave a message.