Bring another one free of charge
免费换一份

Is there anything I can do for you?
我能帮您什么忙吗？
Yes. The fried chicken is too hard to eat. I suggest you bring me another one free of charge.
是的，炸鸡硬的没法吃。我认为你应该给我免费换一份。

Well, I think you should go for our manger. I will call him here.
嗯，恐怕您得找我们经理去说，我会把他叫到这里。
OK. I will talk to him directly.
好的，我直接和他谈。