If you file a proper claim with DL, it is liable under its own contract for repair or replacement. A very good chance that it will simply ship you a new case or offer you something equivalent (which you may refuse). You may then hang onto or repair the damaged case as you choose.
For those who may be flying into a large station such as ATL or JFK, and have a standard case you don't particularly care about, DL typically has generic bags in stock and will simply issue you one on the spot. Again, you may refuse the offer, but for standard items where all you care about is functionality, you may do just as well to take the new item.