Can I cancel an accidental app purchase on iPhone?

Accidental purchase , bank has insufficient amount , cannot report for refund since processing/pending to deduct money. Im stuck now where i cant cancel or report refund no option too where do i go or what can i do

Cannot download any app now, how to cancel order or payment which hasnt been made? Accidental purchase app credit and i havent use the app credit the game is willing to refund but cant deny order.

[Re-Titled by Moderator]