REFUND U/S 77 OR U/S 54 - Goods and Services Tax - GST

Dear Expert, i have filed my GSTR-1 for the month of july 2017 correctly. all the invoices shows the liability under IGST but when i have to pay the gst through GSTR-3B i wrongly pay the tax under CGST and SGST. now, i got notice ASMT-10 it shows that i have not pay the gst liability as per GSTR-1 which shows IGST liabilty. Further, i paid the IGST and going to apply for refund which i have wrongly paid under CGST and SGST but when i am going to file statement-6 we got two column 1. transaction considered previously and 2. transaction considered subsequently. i filled all detail as require the column (transaction considered previously) as i filed GSTR-1 which is correct as i said above. but when i go to fill transaction considered subsequently i found that my my both column will be same and refund has not been generated now i need to know how i go to apply for RFD-01 through statement-6.