Will I be able to get a replacement iPhone 5S?

For some weird reason it won't hold a charge (it charges super fast and doesn't hold for more than a few hours) and while it's charging, the touch screen completely freaks out and glitches. It's still under warranty and has insurance on it, no shock damage, no water damage, the screen is perfectly fine (I have a protector), no cracks or scratches. I have an appointment tomorrow at the apple store, but I doubt anything can be done to fix it, so I want to know if I can get a replacement for free because nothing was my fault?

If it is still under warranty they will either fix it or replace it (though they usually try to fix it first).

If it's under warranty, you mail it in to the warranty center, pay your deductible, and they send you a refurb.

You don't get a brand new phone.