Valentines day McFlurry

On Valentines day I received a notification saying that I could redeem free mcFlurry on that day ,when I finished working I went around to McDonald's to order myself a Big mac meal and redeem my free mcFlurry and the promotion ended and I couldn't redeem the offer ,why did you send a notification for that specific day but you can't even redeem the offer ,I just cancelled my order and left