Nike Shoes' Stitching Came Apart in Under 7 Months

I purchased a pair of women’s Nike casual shoes from the Intersport Piazza store 6 months ago, and within 7 months, the stitching has already come apart. When I tried to return or exchange the shoes, the store refused, which is unacceptable for a brand like Nike and a trusted retailer like Intersport. I’m requesting a full refund or a one-to-one replacement for this defective product. Please address this issue immediately.