I'm truly sorry for the inconvenience. We'll dispatch our housekeeping team immediately to rectify this.

We apologize for the oversight. Would you like us to clean your room right away, or is there a specific time that works best for you?

Well, some people have different standards. Are you sure it's not clean, or are you just being picky?

Oh, that's a surprise! Perhaps the room decided to have a little party while you were out?