I get a call from this number multiple times a day. I don't answer and just let the voicemail pick up and I don't get any messages. I know to just send them straight to voicemail next time I am physically in the office.
I may be getting the same calls at home and the most annoying thing is they call late at night. I may have to pick up some time and ask for their personal phone number as well so I call them and bother them at home as well. I have used this tactic a few times and the telemarketers quit calling. They usually respond that it is not in their company policy to provide home numbers then I respond, I am sure you would not want to be bothered at home either so never call me back again... :)