Calls a couple of times a week and leaves no message

I get these calls once every 3 months. No messages left.

This is the answering service for Dermatology Associates.

I get calls from 503 416-7125 and when I answer no one is ever there.

Dermatology Associates

They keep calling asking for someone that does not live at my address. I've spoken with them and informed them that no one by the specific name lives at my address. They continue to call. Today, when I called them, they put me on hold.  I hung up after 4 minutes. I looked up the local phone number for the company, and the gentleman answering the phone said he would remove my number from their system. He implied that they have some type of automated calling tool that contacts their "customers" but he didn't explain why they would be calling.

Who is this Caller?

Who is this Caller?