I am as well disapointed with Hyatt online BRG. I submitted two claims for PH Vienna, using booking.com. Both got denied for :
brg 2 : they were comparing a hyatt advance fare to a booking flexible (aka daily rate) which i asked they compared it to in my mail.
brg 1: they couldn't find the same rate i did apparently. which i was still showing even after i got the rejection email.