How to cancel an unwanted subscription holding up the App Store?

Are you seeing a Pending Charge that has not been able to process yet? You cannot cancel a pending charge because you have already agreed to pay for it. If it was a free trial, you would have seen the message on the screen that required you to double click the side button, followed by authentication with Face ID/ Touch ID or Passcode, and it said to avoid a subscription charge make sure to cancel at least a day before the renew date.

For a pending charge, you will need to pay for it either by adding a valid payment method, or using Gift Cards to add funds to your account. After that it is possible to cancel the subscription to avoid future renewal and/or try to request a refund for the charge. In most cases all transactions in the App Store are final, but at times Apple may provide a compassionate refund. It should never be expected though.