Riot girl tristana and Dreadknight garen and others...

Recently i hit level 30 and i want to try to swim in the ranked waters but as we all know we must have 16 champs and thats my problem.I have lack of champions and i need more, i want to make my champion pool even biger so, i tried to get riot girl tristana and dreadknight garen but the codes didnt worked out for me i dont know how can i fix that so im trying to reach out for you.It would be my bigest Christmas present and and my motivation. Hope you had a wonderful Christmas and i wish you a happy and sucsessful New Year!