They called me 5 or 6 times two weeks ago. I answered twice and told them they had the wrong number. The second time they asked me if I was "Rebecca" from some city like 3 hours away from me. Again, I said no, and that I'd like them to stop calling. They called again today...luckily I was in class or it would have been time for me to mess with them. Kind of hoping they call again :D
Anecdotal information: I've only ever heard what sounds like two voices...African-American man and African-American woman.