If you already had problems trying to Zero it in and wasn't able to, and if you dropped it from about 4.5 feet I would say send it back to Nikon, it shouldn't take any more than a couple weeks to get it back, That's what I would do, then you would know the scope is well tuned and working properly when you do try to sight it in.
but if i take it out shooting this friday and it shoots fine then that a forsure way to know it aint broken instead of sending it to nikon and taking 2 months to get it back do u think that is right or there still a chance of something wrong wit it ??
Maybe you should give Nikon a call and talk with Customer service, just ask them how long it will take to get it back after they recieve it, you can call them at...
Nikon Film & Sport Optics Technical Support
6am-4pm PST Monday-Friday
Either way, Good Luck and let us know how it goes.