U.S. Polo Assn Bag I Bought for School Had Poor Stitching and Keeps Falling Apart

I bought a U.S. Polo Assn. bag for school 1.5 years ago. The stitching started to come undone, so we sent it for service. However, the stitching was poorly done, with loose threads left behind. Not long after, the stitching began to come undone again, causing issues in multiple areas. It's frustrating to see such a low-quality product after spending so much money. Now I have to send it for service a second time, and there’s no guarantee the stitching won’t come undone again. I don’t understand how long this will continue. It takes 2-3 weeks for the bag to be inspected under warranty, and during this time, I’m forced to use my old bag for school.