This number is the World Wildlife Fund. To get off their list, send an email to:
[email protected]
Tell them you want to be removed from their call list. Also request that they don't sell or give your number to any 3rd party.
They responded in less than 24 hours to me and confirmed my phone number was removed.
I donate to WWF, so they are in compliance with the Do Not Call because I had an "existing business relationship" with them. But if you donate or not, you have the right to request to be removed.
Good luck.