Here's how to give them a dose of their own medicine.
Call back that number from an unlisted landline, follow the prompt. At the end you will be asked to leave name, number and preferred schedule to meet them. Give false name and number, and it is important to pick the earliest date. Then they would have their reps/telemarketers listen to messages that are requesting early meetings - thus efficiently wasting their time and money as well - payback!! I left them 4 messages 4 different names from the series Heroes :), earliest times. Leave as many as you can, you dont have to wait for their sales pitch the second time around, just press 1, 1, and 3-digit code.
I received a phone call today to my private Colorado cell phone number. I too did not recognize the phone number so let it go to voice mail. Received a message from "Mary...the pre-recorded voice" stating the form I filled out at one of their promotional events had been selected and my spouse and I were the winners of two round trip airline tickets as well as three nights accomdations to three locations of my choice. "Mary" did identify herself as being with WestStar Marketing as mentioned above.