Since someone mentioned the dry cleaner brushing, made me think that it could also be the pressing equipment. Maybe they are stretching the shirt over a stand that is too large. I had a dry cleaner years ago that was wearing holes in the cuffs of all their customers' shirts. Turns out there was a screw head sticking up from the pressing machine that was wearing away the fabric in the same area each time. I don't know why no one noticed until shirts started showing the damage. Maybe ask them what their process is exactly, and also whether you can see the equipment?