I don't know if this has been posted before but there is a trick to getting new phones versus refurb's from Sprint, although time consuming, it works much easier, generally, and with less headaches from the reps and techs.
If you have a problem with your phone take it in to the Service center tell them, they will do the diagnostic stuff and either tell you it's checking out fine and ask if you want a refurb or upgrade (if they don't say anything about getting a refub, just ask..don't just automatically start demanding a new phone you'll already start your headaches early) I've never had a problem with them givin me a refub after they tell me the diagnostic comes back fine if I say that I just don't trust it because although the d's coming back fine it's just not working right.
After you get the refub, if it's good use it till it's not, if it's a POS then take it back the next day and tell them the refub they provided is unsatisfactory in _(blank)_ ways. They will generally offer you a new refub, or upgrade, again. (I say "generally" cause I've noticed that customer service in-store is subjective to area, if worse comes to worse I've never had trouble with the corporate customer service especially if you start threatening to go to another provider (but I would save that threat until you've gotten at least 3 refurb phone, as I said previously time consuming)
After you have had 3-4 refurb phones the corporate office will give you a new phone if the refurbs have all been unsatisfactory. I have had them even tell me on the phone that they technically can't give out brand new phones until you have had at least 3-4 refurbs with less then stellar results.
As I said it is time consuming and a bit of a pain but if they are still resistant to a new phone after having 3-4 refurbs your last resort should come down to calling corporate and threatening to switch service providers, you WILL get transfered through the ringer of reps and told this and that but once you get to the last person they will tell you ok since you have brought your phone in so much you can go to the service center and I will put a note in the computer and they will provide you with a new unit, or they will mail a new one to you...and if one rep is an A$$ or doesn't seem receptive to send a new phone, simply hang up and call again and speak with someone else, cause I know that they will do it. I've had sprint since approximately 2000 and have gotten a new phone with every available upgrade and some without having upgrades available it's just about working around their corporate policies, reps can't control what the policies are but you can help them help you by having a paper trail that you are trying to get something fixed and it never does so then they have to appease or lose you as a customer, they'd lose alot of money if they gave everyone a new phone, everytime one came in with a problem...
Hope My Experience Helps To Some