Why Yosemite still reverts screensaver to Nat Geo pics?!!! How fix?

This is sending me crazy - I dont want to see National Geographic pics in my screensaver and it wont save Photos whenever I select it.

*****Why are you not fixing this Apple!!! This may seem small to you but its totally infuriating to the rest of us and bad customer service as people have been telling you about the problem since this was first launched!

Help - Does anyone have workable solutions?