Why are all my photos wiped out after backup?

My brother and I upgraded to the iPhone X yesterday and backed up our phones. My brother even stayed at the store to wait for the phone for a good hour for the phone to back up. I was only able to recover my photos as far as “November 2017” and my brothers phone had all his images wiped out. This is not just a couple photos missing now it’s a whole gallery. My brother had lots of photos that were lost of our two dogs that passed away and now all I really want is to get them back. Charge me however much money, is there anyway Apple can recover both of photos?