I bought a new Apple charger for my phone and it works fine but it doesn't keep my phone charged very long at all, with my old charger my phone would stay charged for hours! With this one it's almost dead after 1hour. can I get the charger replaced?

You could return the charger to WalMart and try your luck with another.

Not sure what kind of limited conditional replacement they offer a buyer.

Also, you may consider an inspection of the iPhone by an Apple qualified

service or product expert, at an Apple Store or at an independent Apple

trained service department; especially if it has a warranty still in place...

You may try a reset of the phone, to see if that helps the power situation.

There may be a chance that something in the hardware of the Phone may

be weak or failing. At some point, a percentage of product may, as most

consumer goods essentially are somewhat disposable after an expected

cycle of usefulness. If the unit has past its warranty, there may be a lower

cost replacement (considering retail value, not contractual cost) you may

inquire about from Apple.

So those are some areas to consider looking into.

Good luck in any event...! 🙂