I a would like to contest a charged incurred last week Property*********Reservation ID...

I a would like to contest a charged incurred last week Property*********Reservation ID*HA-*V**S*. I initially booked the reservation for * guests. Subsequently a few family members asked to join and I said yes as we had reserved the entire house. Since the confirmation email asked that we notify them of the final number staying I sent an email and let them know we had * more coming. I was shocked when I received a bill for an additional $*** for the additional people. Nowhere on the website or the confirmation letter (see below) did it say there would be an additional charge. I want that money refunded as I feel there is a lack of transparency in the billing. I would not have allowed them to come, or charged themthe $*** if I had known as this is significantly over my budget. **Your reservation includes accommodation for up to *** guests . If you would like to accommodate additional guests , please get in touch with us prior to your arrival. **I am trying to resolve this privately as I think it is clear looking at the website and letter received that it does not list this charge anywhere. Can you assist or do I need to go another route to get my money back. Thank you, gail leos