If it is a general minor error, you can keep the order and contact the merchant to explain what needs to be changed; if it is an important error, you can cancel the order and refund it online. In most cases, the cancellation of the order will take effect immediately, but because the payment has been collected by the bank or card organization, it will take a few days to complete the refund. Some banks may charge a handling fee, this will be borne by you.