You have issued 2 DN invoices
1 for Usd 50
1 for Usd 30
Even if we calculate with Usd 25.00 profit share per container we have been overcharged for Usd 30 as total should be Usd 50 and now you have debit Usd 80 in total
Credit should be Usd 30 instead of Usd 20