You could definitely try totally exiting the game and go back in. Are you aware that mounts and pets should appear in your collections screen? You will need to "select" it in your collections screen before you can mount it using you controller key.
HOW DO I COLLECT MY IN-GAME ITEMS THAT I HAVE PURCHASED FROM THE CROWN STORE?
Updated 03/17/2015 10:44 AM Published 01/21/2015 08:43 AM
The item can be found in the player's inventory or collections immediately upon purchase.