Good coming , sir . What can I do for you ?   I'm Mr . Bob , Room 309 . I'm checking out today . Can I have my bill now ?   Certainly . Please wait a moment . Here is your bill .   What's the 30 yuan for ?   This is the charge for your laundry service on Nov . 20thA   But I did't take any laundry service during my stay here . I think you have added someone else's .   Would you mind waiting a moment while we check it with the department concerned ?   I don't mind waiting as long as we get this straightened out .   I'm very sorry , Mr . Bob . There has been a mistake . We'll correct the bill . 