(works contract)Advance tax adjustments with final invoice

Mohammad chisty (46 Points)

31 May 2019  
somebody help me out.,

works contract i.e service provider,
last year advances paid(AND Shows Table11A,GSTR1) every month ,

Aug- 3 lakhs
Nov- 4.5 lakhs
Jan- 6 lakhs, Total 13.5Lakhs.

we pay tax every month when we received advance,
3B,GSTR1(Table 11A,B)

now Final invoice rised in March-19 for 13.5 Lakhs single invoice of total advances received.

now my question is..,

where to show invoice in GST1(opposite party want to see in 2A),

and no need to pay tax in 3B-Return(earlier paid).

waiting for reply Thanks in advance