When you place an order, a hold is placed on your bank account. This may appear as a debit or a pending transaction, depending on the bank.
This request is simply a deposit and will only be debited if your order is shipped.
If the order is cancelled an "authorization cancellation" is performed, which instructs your card issuer to remove the "payment authorization", making the funds available again in your account.
Unfortunately, we cannot control the time it takes for your card issuer to cancel the authorization. This is determined by their own internal policy. It usually takes several days.