How can I get a refund for a game festival bug that prevents me from receiving rewards on iPhone?

I spent $9.99 for a game festival, but the game have bug that I can't get my rewards in October, and I ask the developer of the game, they just ask me for the screen recording, but I don't record(who always recording during the game?) and they just said that the game is no problem, and I ask the apple for refund two times, but they refused my apply, I think it is not fair to a game player, how can I do?

[Re-Titled by Moderator]

Original Title: I spent $9.99 on a game festival, the game festival have a bug that I can't get my rewards