Once an order has been shipped, it cannot be cancelled at all. Discount coupons or vouchers are only meant to be used once and will still be considered used even if you cancel the order.
In the event of a cancelling, any loyalty points you had used to pay for the order will be reimbursed back to your account.
If a return or cancellation is authorised by customer service, the refund will be processed within 72 hours after receiving the returned material, pending inspection of the goods and their packaging. Any goods that has been tampered with will be deducted before reimbursement.