gst interest and panelty

As such interest is to be levied @ 18%for non payment of tax , however in case of non filling of gstr 3B no interest is to be levied if payment is made on due date. Penalty per day Rs. 100/- is to be levied if gstr 3B is not filled on due date..Refer section 51(1) of CGST ACT, 2017 it is clearly stated in tgat sub section that interest shall be leviable @ 18% for non payment of tax and not for non filling of GSTR 3B