If it won't charge at all, no matter the cord, your battery is probably in need of replacing.
If the device is under warranty, then you don't want to open it up on your own, or have just anyone do it, as that will void the warranty. In that case I would contact the manufacturer to see about a repair or replacement.
If it isn't under warranty, well then you can look into doing the replacement or take it to a local repair shop to get it done.