Called on July 17 and didn't leave a message. Caller ID just showed "Business Center." When I called the number back about 30 minutes later, there was a recording that said this number is not in service. Sounds like a telemarketer or a scam.
That number is used to call on behalf of political campaigns or charities, neither of which is covered by the Do Not Call list, so if you're on the list but they are calling you, it may be for that reason.
If the call is being made by a 3rd party on behalf ot eh charity or campaign, you can still ask them to place you on their do not call list.