NOT National Geographic calling; it's a rip-off subscription business that may also try to convince you that a subscription is up for renewal. If you do order a magazine, it will cost 3-5 times more than a subscription directly from the magazine.
Warning: If you've ever ordered a magazine by credit card on the internet, contact the credit card company and get a new card. (Probably a good idea to do periodically anyway.) I didn't pick up until too late that I had been billed twice for a magazine I had canceled - total $124 for a magazine that could have been ordered directly and gotten a special for $10. That same outfit followed up with a renewal notice to me for National Geographic, which I've never subscribed to in my life. Had I not changed my credit card number, a subscription for $100+ would have appeared.
Calls go to my voice mail, they never leave a message. Added hazard: When you pick up a solicitation call, and especially "click X if you want to be removed from the call list" from an automated call, it simply validates a phone number is still active. That gets us on even more call lists.
There's gotta be a way to have the "Do Not Call" registry penalty imposed.