Called today on cell phone. I did not answer. No message left. I put these unsolicited calls in my "contacts" list labeled as junk1 junk2, junk3, etc so that I will never be tempted to connect.
I did call back and Got " This is a recorded call. This is Dan. How may I help you?" I just said you are a telemarketer and I am on do not call list and will be happy to report him and hung up.