You will automatically get promoted to higher Arenas once you accumulate the necessary number of Trophies.
Once you do, you will receive the rewards for advancing from the Arena you had previously placed in, and you will begin to battle players and receive rewards from your new, higher Arena.
You can only get an Arena’s final rewards once, no matter if you get demoted and promoted to the Arena again.
How do I reach the higher Arenas?
Last Updated: 592d