Delivery and Customer Service Issues with Stradivarius Online Order

I ordered a product from the Stradivarius website on 26.06.2024 and paid ₺2,140. However, the product has still not been delivered to me. The website shows that it has been shipped, but the courier service says there is no package under my name. The tracking system on the site is not working, either. Customer service has been promising to look into the issue for a month now, but there is still no solution. I cannot return the product either, as customer service says they cannot cancel it because it hasn't been delivered. I have received neither the product nor a refund. I cannot even find someone to resolve the issue. They also mockingly suggest that I use my consumer rights. Such a well-established company is disappointing its customers with its lack of follow-up and interest after the sale.