ADJUSTMENT OF GST SHORT PAID IN FY 17-18

Dear sir/madam
one of my client while filing GSTR 3B OF FY 2017-18 Output tax liability was short discharged and the short discharged amount was paid through GSTR-3B OF the FY 2018-19. Now the department is asking to pay again the short amount along with interest and claim refund for the Excess amount paid in FY 2018-19.
is there any circular /instructions to adjust short payment in subsequent GSTR-3B..

THANK YOU