ReservationDesk.com review: Additional unquoted charge

On 2/2/2025 I booked two rooms at Southwinds Motel in Key West, FL through a website I believed was associated with them, ReservationDesk.com. The confirmation e-mail I received states "We have charged your credit card for the full payment of this reservation. Your booking is guaranteed and paid in full." The e-mail lists $191.56 as taxes and fees and a service charge of $17.99. When I arrived at the Southwinds Motel I was informed that I owed an additional $112.52 which included an Amenity Fee with sales tax and county tax. I immediately tried to contact ReservationsDesk.com at the number provided on the email, 800-434-1659 and ended up asking for a call back which their automated system assured would be forthcoming as soon as possible (as of today, 6/13/2025 I have not received a call). The motel was able to track down a different number which someone did answer. When I spoke with the representative from ReservationDesk.com he tried to tell me that the email they provided showed I would owe additional fees. When I informed I was holding a hard copy of the email and that no where did it contain what he was claiming, he tried to say the hard copy had not printed correctly. I have since retrieved the original electronic copy and, as I fully expected, it is identical to the hard copy. The verbiage at the end of the ReservationDesk.com email contains the following:
"TAXES & FEES
This charge includes estimated amounts the travel service provider (i.e. hotel, car rental company) pays for their taxes, and/or taxes that we pay, to taxing authorities on your booking (including but not limited to sales, occupancy, and value added tax). This amount may also include any amounts charged to us for resort fees, cleaning fees, and other fees and/or a fee we, the hotel supplier and/or the website you booked on, retain as part of the compensation for our and/or their services, which varies based on factors such as location, the amount, and how you booked."
Based on this statement in conjunction with the earlier statement that my booking was "paid in full" and the fact that ReservationDesk.com had already collected $191.56 in taxes and fees, I believe ReservationDesk.com should have paid the $112.52 that I had to pay to Southwinds Motel. The staff as Southwinds Motel stated to me that this situation arose because ReservationDesk.com is a third party and, had I booked directly with them, would have been included in the room rate.
In addition, ReservationDesk lists Utah as their place of business but the transaction details shows 1111 Expedia Group Way, WA 98119. I have to assume ReservationDesk is a part of Expedia?