Quality of shirts

Paid almost N$500 for an Old khaki shirt and in less than 2 months the left shoulder had chaffed through and had a tear. Took it back to the store to have it exchanged and had the manager tell me that she has NEVER seen this happen in her career. Obviously I was in the wrong and had torn the shirt somewhere, although the tear was exactly on the contact spot of the elbow and in the opposite direction of what a tear would have been had I walked past a sharp object. Thanks I will never buy a shirt here again. Woolworths would have replaced this without batting an eyelid.