I have lost over 1000+ of my phones from iCloud when upgrade to 8.3

i think not only me who met this critical issue - photos are lost from icloud. i'm wondering whether apple is going to solve this and how. are we able to get our photos back is the most key point that i care about. coz none of them can be re-taken ever. i even pay for my cloud space. how can i trust cloud service afterwards?