Will Apple replace my iPhone 5 charger?

Will Apple replace my iPhone 5 charger?
My charger wasn't always finicky… But the past few days I would have to wiggle it around to get it to charge now no matter how much I adjust it it will not charge… I'm fine buying a new charger if I have to but I know my phone is still under the 1 year warranty. I was just wondering if apple would replace it? If so how do I go about getting it replaced? Do I go into an apple store or the future shop where I bought my iPhone or do I have to mail it?

Added (1). How did I cause it? I use my charger normally… Am I suppose to not charge my phone and leave the charger in the box forever?

No, you caused the short, you will need to buy a new one

Just buy a new chord on amazon, they have some really low priced ones.