Your story is not unique. I had a friend send his Monarch and they sent him a brand new one within a week or two. Seems like Nikon's service has gotten a lot better over the last couple of years.
Overall, <span style="font-style: italic">outside of SuperSeal110's experience</span>, this is good news as I'm looking at a new Nikon Monarch 8-32x50 right now.
Same thing just happened to me. I returned a Nikon Monarch 6-20x44 AO which showed a wandering zero and tracking problems and got back the new Monarch 5-20x44 with side parallax turret. A good deal indeed !
I had a windage knob break right off on a nikon 6-24x50SF. all and all i would say it was about 2 weeks they sent back a brand new one. great service nice optics for the price. i was a little concerned to have a knob break under recoil. this scope hasnt seen the field and was just bench shooting.