GST: Can a challan generated online be modified by a registered taxpayer?

If a taxpayer has incorrectly generated a challan, he has an option to generate a new one for payment of taxes

Under the pre-goods and services tax (GST) regime, exporters were allowed to obtain duty-paid inputs and export the goods on payment of duty (after utilising the input tax credit). Thereafter, an exporter has an option to claim refund of duty paid on export. Does an exporter have the option to claim refund of duty paid under the GST regime? 

GST law prescribes an option to the registered taxable person to either export goods without payment of integrated tax under bond or letter of undertaking and claim refund of accumulated input tax credit, or export on payment of integrated tax and claim