Booking.com

I booked 4 hotel rooms for four families on dec 27-28th for two days using booking.com website. I got confirmation by email for the corrects dates. When we reached hyatt on sunday Hyatt said our reservation is not in there system. We showed the confirmation and Hyatt said booking.com messed up and they dont have any request. When we called booking.com they say Hyatt messed up with our reservation and it is Hyatt's problem. Hyatt and booking.com both blame each other and No resolution so far. Please suggest what action should be taken in this case and whom we should be complaining. Also suggest what legal rights as a customer we have ?