Mystery Solved. These calls are NOT coming from The Heritage Foundation. They almost certainly originate from telemarketer The Heritage COMPANY. http://www.theheritagecompany.com/
We continue to get a call from this number and they don't answer even when you say hello quite a few times. They never leave a message on the answering machine. Today I happened to be home and waited quite a while after saying hello and it was a woman who did not identify herself looking for my husband and I told her he was not available and that we do not allow solicitation she said she would note that, but she would call back later. We do not wish to be solicited!