Are these tires worn out or was it rather a manufacturing defect?
It looks like age/exposure related failure from what I can see. If it is a defect the shop where you purchased them may pro-rate them on new tires. If they do this it would be a good will gesture on their part. I worked in the retail automotive tire world and it is nearly impossible to get a defect related replacement from the manufacturer. They blame under /over inflation, road hazard, sun exposure etc.