My New GAP Shirt Had a Black Streak in the Fabric After Just One Wear

I purchased a "Linen Blend Easy Shirt" from the GAP Online store, to be delivered to my address in Odunpazarı, Eskişehir, and the product was delivered to me on June 16th. When I wore this product, which came under order number 3261230339515634p1, for the first time on June 17th, I noticed a distinct black streak on the fabric, separate from the pattern. The product had never been washed — it had only been worn once.
Since I believe this defect, which appeared on the first wear, is manufacturing-related, I am requesting that it be evaluated under defective product coverage. I expect a solution in the form of either an exchange or a refund for this product.
I kindly ask that the necessary investigation be conducted, that I be informed as soon as possible, and that my problem be resolved.