Called the number back to see who it was after Caller ID only showed the number. It rang twice and a live female voice answered with "Good morning, thank you for calling DKA..." A quick Google for DKA and debt returned Delanore, Kemper & Associates LLC out of Atlanta (though the number is out of St. Louis, MO). Website says their specialties are Commercial/Industrial accounts, Consumer/Retail accounts, NSF checks, Credit card portfolios, Media/Advertising, Property management claims, Wholesale/Distributors, Skip tracing, Medical collections, and Automotive suppliers. They have an entire page dedicated to third-party collections
http://dkallc.com/8.html.