Did some research. The number comes out of Southfield, MI. They claim to be a debt collection agency collecting on behalf of SureTel Wireless (that's what their answering service says).
So... if I'm getting these calls, and I know for a fact that I've never used SureTel Wireless, then I can reasonably assume that any calls from this number are actually part of a debt collection scam. They figure they'll just blend in with the rest of your debt and get paid off without you even knowing you're being scammed. In fact, you feel like a productive member of society because you're getting square on a debt, but in reality, you're just being used, abused, taken advantage of, and all the while, they're laughing at you and thinking how stupid you must be to believe their lies.