Looks rather like they caught the end on a belt sander after levelling it.

Apart from sending it back, I'd either stick some maple veneer on and sand it flat, or sand the the whole base of the heel down flat. You may find that the neck angle is a bit shallow anyway, I know mine was/is, so it may well benefit from a sand to tweak the angle. But it's not that easy to do whilst keeping the heel perpendicular to the sides of the neck.