Dear Mr. Jonathan,
I was surprised to receive your bill of last order. According to our agreement, your commission should be 5% per order. But the unit price of latest orders already included your commission, you added the commission again in the total amount. Therefore, your commission became 5.25% on latest orders. Please re-calculate and send another bill to us as soon as you can.
我接到你最近的订单的账单时吓了一跳。根据我们的协议，你的佣金是每个订单的百分之五。而最近订单的单价已经包含了你的佣金，你又在计算总价时再加上 5%。因此，你的佣金变成 5.25%。请重新计算，然后再尽快送另一张账单过来。
Looking forward to receiving another bill very soon.