My iPhone will not charge via wall charger?

I have an iPhone 4S that will not charge via the Apple Wall Charger. I took it to my local Sprint store and the guy there said it is the cord and he could sell me a new cord, then later I took, it to the Mall of America Apple Store and they said it is the device itself.

I have already tried a reset (to no success ) and am doing a restore, what other suggestions do you have?

If you have actually tried it with a new cord and a new charger, and it still doesn't charge, then it's 100% certain that there's a problem with the phone itself. If you're lucky it just needs a new battery; most local phone repair places can swap the battery in a few minutes for less than $50.