Cancelled Canon Pixma G3416 Order Still Shipped - No Refund

I purchased a Canon Pixma G3416 Multifunction Photoink Inkjet Printer from n11.com and canceled the order on the same day. However, on October 23, 2025, the canceled order was sent out for delivery to me via DHL. Although I informed N11 about the situation, the courier company requested a return code for the product I never received, but N11 did not provide one. Despite canceling the order on the same day, neither the product was returned nor was my payment refunded. N11 keeps claiming there is a system error and avoids resolving the issue. There is no solution, no refund, and no follow-up. They do not contact the courier company or take any action. I demand an immediate refund of my payment.