There is a duplicate figure which is carried this fortnight billing also. 15th Sep 16 is duplicated in both the invoices so please remove it & resend with revised one. Request you to make the 15 days invoice as below
Day 1 to 15 Day – First Invoice
Day 16 – Last day of the month 30 / 31 depending upon the month – Second Invoice
Please ensure that this is followed else there would be a problem in reconciliation at the later stages.