Owner fights for R10.00 in my office.

I placed an order telephonically to arrive at my office. Order was Pamodro pasta, choice of pasta to have i choice penne, also asked for Parmesan cheese on the side and the order was booked with the owner. on arrival the pasta was fine, cream cheese was given in a box and was charger incorrectly on the order. The bill was handed to me to pay R95.00, Pamadro =R41.00, Penne = R19.00 and the cheese was R 35.00. i then agreed to pay for the pamodro =R41.00 as that's what i ordered and gave the guy who delivered a tip. the owner then disagreed and came to my office to fight with me for and extra R10.00. i feel that it was unacceptable to be paying for an incorrect order and to pay that amount. the owner should have called me to inquire on the situation and not to come to my office and infront of my fellow colleagues.