GSTR 9 (Table 8A issue)

As you know, table 8A is an auto-populated figure regarding ITC, and we are also provided excel sheet to assist us in determining how the auto-populated figure is derived. But I am facing issue where auto-populated figure of ITC is Rs. 1584000 approx while ITC as per 8A documents details is Rs. 2038000 approx(which is correct)
Thus, there is mistake at department end. How can I rectify it now, because I also raise grievance, but they dont assist us.