Can I return an iPhone 5 charger from T-Mobile?

I bought an iPhone 5 charger from T-Mobile five days ago because I had lost the original one from Apple. Now I found the original charger and I was wondering if I could still return the charger from T-Mobile?

Got the receipt? If so, go down to them, and return it. WHY ARE YOU ASKING ON HERE, ASK AT T-MOBILE!