Mystery Solved. These calls are NOT coming from The Heritage Foundation. They almost certainly originate from telemarketer The Heritage COMPANY. http://www.theheritagecompany.com/
Caller ID says Heritage but it's not the Heritage Foundation. This number calls several times a day, every day. Never answers and never leaves a message. Once there was a woman's voice who asked someone near her what time it was. We, too, are on the Do Not Call list but as every Govt. program it doesn't work.