Nikon Warranty and Repair Question

Hi all,

I sent in two of my lenses: 24-70mm and 70-200vr2. The 24-70 has a stiff zoom around 28mm and is softer than it should be. The 70-200VR2 has an aperture that doesn't open at all, it is always at 2.8.

Nikon sends me work orders for both and claims that both are due to impact damage. $700 for the 24-70mm and $691 for the 70-200VR! I have been so gentle with these lenses so it is hard for me to believe that I have damaged them from impact. There is absolutely zero signs of impact that is for sure and I've never dropped these lenses or handled them too roughly.

What should I do? I haven't called Nikon yet because I'd like to hear if anyone else has had this experience and what they have done about it.

Thanks!