We have made SEZ sales on July 17 and because of NON-LUT we have paid IGST, now while entering in GSTR 3B we have put the figure in 3.1 (a) instead of 3.1 (b) and filed the return so we are not able to apply for a refund. How to solve this issue? CBEC is saying that show the SEZ sales in 3.1 (b) of current month GSTR 3B and reduce the Turnover of 3.1 (a) by that amount. But the Financial Year is already closed and how we can show last year sales in the current year?