Purchase returns should not be mixed with Sales data

The Purchase returns are being added to sales in GSTR1 summary. The Purchase returns are considered as Debit notes and are being added to tax payables . This is not a correct way to do. The purchase returns should be deducted to the totals of Purchases. Not to be mixed with sales data at all. kindly rectify this issue at the earliest as i am losing lot of time segragating the data while doing my GST returns