error on commission

It limits the commission of the% payment to an amount, for example a sale with a commission of 33.4% whose sale price is 5,000,000, should allocate 1,670,000 of commission, but allocates 1,000,000. And so if I assign a sale of greater amount for example 50,000,000 allocate the commission for 1,000,000.

The page I need help with: [log in to see the link]