If a customer requests to cancel their order before the item goes to production, the item will be marked as cancelled and not sent for fulfillment. You will not be charged for these items. However, in order to fulfill items as efficiently as possible your orders are sent to production within 24 hours so may not be available to cancel.
Currently, our Customer Service team are the only ones that can prevent an order from reaching fulfillment. If the order is canceled in Shopify, nothing will stop that order from being fulfilled, unless we are contacted.