Looking at the photo I can see there is no damage near the seams, no failed stitching and no fatigue in the cloth. This generally only leads to one cause and that is contact with a sharp object or kite line. Disappointing as it is to damage a kite, this clearly isn't a warranty issue sorry.
I've been a kite repairer for 10 years now and have seen pretty much all there is to see when it comes to faulty kites and damaged kites. It would be good to see a photo of the damage before the repair. I might be able to assist if it's a legit fault.