An overfiled nut wouldn't happen to be covered under a warranty, would it?

I got a Yamaha BB4 Fretless this past Monday and the nut is filed WAY too much -- there's even a spot behind the E slot on the headstock side of it where the file took a bit out of the fretboard. There was a lot of buzz on the bass with the stock strings on, and the TI's I have just sit flat against the neck when brought up to tension.

Pictures:

What should I do? If it comes down to me needing to cover this myself, would it be cheaper to take a nut-blank to luthier? Could I shim the underside of the nut, or even better, laminate a wood onto it? Can I get a nut for a fretless from an online dealer? Help, please, I've got a new bass and I can't even play it!

PS: The picture of the chunk of missing fretboard doesn't work