'if' 'and' formula

I am trying to get the payment type to put "partial" if the BALANCE is < COMMISSION AMT(in the first row for that customer), and put "Final" if the BALANCE = 0.

It looks like it works in some instances, but not all.

Please see attached copy of the spreadsheet.

(I have modified each group of payments per customer to reflect the proper row for the commission amount).

Thanks !!