Very disappointing phone call just now with Bonvoy. We booked a hotel at the 35K rate before the category change using points advance. It is now 50K points. Our 35K free night certificate just hit our account, so I called to have it applied. Marriott refused to apply it, saying that they won't honor the 35K rate we locked in with our points advance reservations if we are using a free night cert. They will only honor the 35K rate with points, and they do that by adding the difference in points between the old rate and the new rate to your account balance. Obviously that does nothing to help us since we only have the free night cert, not 35K points sitting in our account. Just really disheartened--the representative and supervisor were not helpful at all.