That is all that it is unfortunately. Now I am stuck with an expensive paperweight. It did fire both barrels without issue but no amount of effort, short of using pliers, would remove the casings.
Derringers not my style regardless of mfr, but curious...did you try poking them out thru the muzzle as with a cleaning rod?
Perhaps a small amount of honing can enlarge the chamber just enough for easier extraction? The chamber should be conical and accurately made, but who would know in a derringer? It's not for long range shooting, and you aren't going to remove more than 0.001" of steel anyway. Here is something to read about the process. It's not like you can make it worse... unless you plan to ship the firearm to the manufacturer again, or to contact a local gunsmith.
If you want a gun like that, get one from Bond Arms. Very high build quality and built like a bank vault.
You didn’t use +P ammo, did you?
I think honing the cylinders might work. Try measuring the depth of the cylinders first to make sure they’re deep enough.