Advance Auto Parts

I purchased a front barren for my ford focus under a year ago and it has went bad and I took the barren which has a year warranty on it and my recepit to the store and the manager (terry) talked to me like I was stupid and like I was trying to rip the company off or something, he tried to tell me that it wasnt the barren that goes in the box. This is the original barren its not my fault that it went bad and feel into pieces. I have my receipt and the barren and I dont understand why they will not replace it when it is under a year warranty. This isn't fair to me in the sense that you all are supposed to replace a part if it is bad and is under warranty no matter what and well I dont have any money and now my car is sitting unusable because they exchange the barren in which they are supposed to... I want an answer on why!