People are not, generally, reachable when and where you need them. A bitter fact of business life is that, usually, the rest of the world works at a different pace than you.

I suggest you drop the phone interview requirement and conduct your research online; a secure, well-tracked form will do. If it's good enough for Nielsen and Price WaterHouse Coopers, it should be good enough for you.

P.S. Professionals might not be too thrilled about the $25 reward as well.

[Edit: Also try not to pester web-savvy communities too much, or someone might decide to feed your link to 4chan and you will get all the high-quality TIME Magazine-esque data your heart desires.]