The steak is underdone!
牛排不熟

Excuse me, I ordered the well-done steak, but this one is so tough.
打扰一下，我要的全熟的牛排，可是这份太生太难咬了。
Well, sir, I think I have made a mistake. I will take it back to the kitchen right now.
先生，恐怕这是我的错，我现在就把它拿回厨房重做。

I think you should be more careful next time.
我觉得下次你应该细心点。
Yes, Sir. I'm really so sorry about that.
是的，先生。对此我感到非常抱歉。