National Park Reservations Non-refundable reservation fee. Montana?

I booked a reservation with the Ahwanee Hotel in Yosemite National Park with this company, primarily because I had no other option and was young and stupid. I later was called to tell me that my requested dates were not available. No charge was made to my account. I later went on line and found another property 20 miles from Yosemite Valley, The Tenaya, and called the lodge to inquire about the available rooms, thinking I was making the reservation directly with the Lodge. Unbeknownst to me, National Park Reservations somehow inserted themselves into the transaction. I cancelled the reservation about two weeks later for medical reasons and later found a charge to my credit card for ten percent of the total fees for the projected stay. I travel a great deal for business and pleasure and have never before encountered similar charges of this amount if accomodations were cancelled before a stated cutoff date. WHO ARE THESE FOLKS? On whose authority do they seemingly control all of the hotel space in our National Parks? They certainly add little or nothing to the experience and their outrageous 10% commision bears no relationship to their effort or value. Do they have an exclusive government contract of some type.? Can one rent hotel space in our National Parks without using their "service"? Regardless, be forewarned. This is about as close to a scam as anything I have recently encountered. If Hilton and Marriott and all other hotel chains can operate without these predatory practices, perhaps National Park Reservations should quietly go away and let Hilton handle park reservations WITHOUT charging a non-refundable booking fee. I would avoid these guys completely, even if it meant not staying at a hotel in one of our national parks. Is this monopoly in the best interests of our country? At a minmum, two or three competitors would seem to be reasonble.