broken nikon d5000
I sort of look at this differently. If Nikon Repair gave you a specific price for the repair, and you paid that price, then they owe your camera 100% repair and operative, or a refurbished D5000 to replace your D5000 camera.
They said they could do it. You paid their price. They attached no conditions to the repair, as I understand your post. If that is indeed the case: now it is their responsibility to hold up their end of the deal.
Just my 2 cents worth.