*written in a neat and delicate handwriting*

I'm afraid I must inform you of the fact that it seems mister Bilby didn't quite do his best with your new lock. It was indeed rather interesting, but I would assume that's not it's only purpose.

I suggest you contact mister Bilby and tell him of this horrible incident, that someone actually managed to open the lock. I hope he will feel inclined to at least try to make something more challenging and inventive this time.