Its going to be tough. Depends on how the animals were packed. If they were packed properly (48+ hour heat packs and heat-gel packs) then it wouldn't matter if it was heated cargo or not. That's the problem. People ship with Air Canada assuming that the heated cargo is enough, and it isn't. Heat packs (generating) and gel packs should always be put in the shipping box. Its just the way it is.
You will have a TOUGH time getting your money back.