Unresolved Refund Issue with Nine West App, Delayed Payment for High-Priced Item

After making a purchase through the Nine West app, I promptly sent back the items I received the same day because they were of poor quality. That was quick with the refund for the cheaper item, but it's been 15 days and the payment for the more expensive item still hasn't been received. Over the course of about five conversations with customer service reps, nothing concrete has been done. It's been a while since I got paid, and I'm getting worried about how things are going. When should I expect the necessary funds to be sent to me, and why is there a delay? I'm looking forward to an explanation and a solution. If the problem doesn't go away, I'm ready to take it to the next level by filing complaints with the right people.