The caller is from Diamond Certified calling to survey you about a certain company that is trying to get or trying to maintain "Diamond Certification" The company I work for is a Diamond Certified company and we have to give our local representative our customer list so they can call and ask how we are doing. If you dont score an average of 80% or better you lose or dont get diamond certification.
Surprise - I'd rather not be called unless it's to invite me out for dinner but if this call really was from "Diamond Certified", it was at least a real person and we did have a relationship with the company they called about.