Huh? You are booked in the hotel that you book.
I value oceanfront not at all. Certainly wouldn't pay almost double for it. You'll see enough of the water diving. You can sit on the balcomy by the pool and see the water.
Casa Mexicana has more than one property. Folks on TripAdvisor have bitched that they thought they booked Mexicana, but were put in another property (like Suites Bahia, mentioned above).