Great question! Our system will attempt to charge the payment method on file a total of three times over the course of 4-8 days in order to successfully collect the amount owing. In the event that our system is unable to collect the funds then the account will go into a frozen state which will bring your store offline until the amount is paid. With that said, if you have a pending amount, and wish to cancel the store, then our Accounts team may be able to help with the closure of your account so long as the charges are not considered valid, and require payment.
If you're still needing assistance with this then let me know by replying back to this post as I'd be happy to verify the account to help get this resolved.