Orders normally get shipped the same day or the next business day. An order can be changed, or cancelled and refunded, if it hasn't been shipped. The Shopify payment system allows refunds to be issued within a day or two of placing the order. So, an immediate refund is usually possible. If you aren't sure about your order, email us, and the order can be held while you decide.
Once an order leaves the warehouse, it can be returned, but you will only get a partial refund. You will incur the initial shipping charge, the return shipping charge, and a restocking fee.
Returning product by physically delivering it to the warehouse is also an option, but you need to arrange the return beforehand. You can't just drop by the warehouse, because it is a secure facility and entry is only permitted when prearranged.