Do not answer numbers you don't recognize and check the number online. If you have a smart phone, you can add the number to your contacts and then send all calls to voicemail. They will never leave a message and your phone will never ring.
Received a call from this number. Automated, telling me I could lower my interest rate. It was on my Mom's cell phone. I pressed 1 as it did not give another option. I was asked if I pressed 1. I told the gentleman that he was calling my 90 year old mother's cell phone and I needed the calls to stop and to be added to a do not call list. He said, "okay, we'll call her tomorrow" I said, "no did you hear me?" He said, "no" when I started to repeat my concern he hung up. I called the number back and received a message that that number was not in service.