Depending on your bank's processing time, it can take anywhere from 5-10 business days (or until the next billing cycle) to show up on your bank account.
If the refund is issued not long after the order was placed, the refund may be processed as a reversal. This means that the original charge will drop off the bank statement altogether, as if it never occurred, and the bank account balance will adjust to credit that money back without a specific line item on the statement.
In addition to a confirmation from us, if you use PayPal as a payment method when placing your order, you'll receive a confirmation email from them when the refund is issued.