how to correct wrong ITC claimed

In last month's GSTR 3 B figure of ITC is wrong..because some of the dealers have issued bills and later on in the same month they issued same bill no with different rate of material..( earlier bill was for higher price)..by mistake both the bills were taken for ITC credit..how to reverse it next month GSTR 3B...the party will not issue any credit note..yhey have simply issued correct invoice with same number in same month..Pl guide in which colum in 3B this amount is to be shown ..and whether interest is to be paid on this difference amount...thanks