Stradivarius Pants Develop Fraying After Just 18 Days of Light Use

I purchased pants from Stradivarius's online app on May 20th and used them fairly infrequently for about 18 days. However, yesterday the pants developed a fraying/loose thread issue, and even though the product is quite new, this situation left me disappointed.
I didn't expect to experience a quality issue like this so soon after purchasing the product. I haven't yet spoken with customer service, but along with this complaint, I am requesting that my issue be reviewed quickly and that a return be arranged for the pants.
Since I believe the product is defective, I kindly ask for assistance with a refund.