I was told last week that they were only complimentary in moderate and deluxe's. However, if you do not request one and one is in your room when you get there, you should not be charged. All that means is that they were lazy and didn't remove it when the previous family checked out. I have heard of this happening more frequently recently.
I wouldn't say a word, use it and if they charge you for it, ask the manager to show you your request. If you didn't request one, they will not be able to produce the request and you shouldn't be charged.