Trial missions bug (Green)

I am repeatedly doing the mission with the 40 take downs over and over again for two days straight, No rewards ofcourse after the first time I completed it and when it shows the next mission to destroy 2 wards in 1 game it vanishes after I finish the match and again the takedowns are back.

I have seen other people are getting bugged aswell, Riot tries to drop the rewards for the players intentionally because they are "loosing" money from the free skin boxes?