How to cancel a processing payment on App Store?

I have a processing payment on my App Store form one of my games, and this causes problems. For example I can’t download other apps nor update them but I don’t want to go along with that processing payment and I can’t ask for a refund because there is no money to refund nor if I tried it will let me I can’t report an issue with a processing payment.

[Re-Titled by Moderator]