Defective tee shirt

My wife bought me a Georgia tee shirt at College Station Sports Store at the Mall of Georgia. I washed the shirt according to the instructions and the patch on the arm frayed amd the stitching is coming undone. WE took the shirt back and the clerk said it was supposed to fray and that the lettering on the front of the shirt would also fray. He said it was supposed to do that. This is unsatisfactory but he refused to make an adjustment. I wanted to get another shirt in exchange but to no avail. The shirt has been worn one time.