"I didn't receive the new Elite League rewards/I lost Cup Points recently."
Elite League rewards can only be claimed following the monthly reset of Cup Points, at the beginning of the month (the first Monday of each month at 10:00 AM UTC).
Please note that the first monthly reset occured on September 2, 2019 at 10:00 AM UTC. The Elite League players' Cup Points are reset according to their progression in the Elite Leagues the previous month. The more Cup Points you have, the more Cup Points you will lose. However, at the same time, the more Cup Points you had before the reset, the more Cup Points you keep afterwards. Also, players at the bottom of Elite League 4 are automatically demoted to League 1 following the monthly reset.
For more information on Elite Leagues, we invite you to check this blog post.