Leaderboard event results are syncronized in all servers same time and it may take up to 2 hours to distribute the rewards after the event ends. If you are still in the rankings and can not get your reward, you can fill out the form and contact us via "Submit a Request" link in the upper right corner.
Also, since the leaderboard list is published simultaneously on all servers, it may take you 2-3 minutes to see your current rank.