Review your Purchase History here:
View your purchase history for the App Store and other Apple media services - Apple Support
Any amount you see in red or noted as Pending has not been processed. You will see what it is for and the amount there. If it is from a subscription, you would have had to cancel it at least a day before it was set to renew to avoid charges. Review your subscriptions here. You must use this process to cancel a subscription at least a day before renewal, not just by deleting the app:
View or cancel app subscriptions on iPhone - Apple Support
You won't be able to continue to use the App Store while you owe money. That will need to be paid first and if the charge is being denied by your bank, it is likely that Apple will deem that payment method as no longer valid and you will need to add a different one.
If you can’t download or update apps on your iPhone or iPad - Apple Support
You can certainly contact Apple directly here:
Contact Apple Support - Apple Support