Flyff Legacy displays multiple confirmation screens and we believe we’ve done everything we can to limit accidental purchases from being made in the game.
Because the game is an online multiplayer game, reversing changes would have adverse effects on other players you've interacted with. As we can’t turn back someone’s progress in the game, or remove features, refunding the Diamonds (or Penya) would provide you with something for free, which we see as unfair to other players.
As such we won't be able to refund any purchase made with Diamonds or Penya, thank you for your understanding!