Sürat Kargo Marked My Package as Delivered but I Never Received It

Sürat Kargo sent me a message stating, "Your package has been delivered," but I haven't received anything at all. I encountered issues when attempting to file a complaint on their website, as the system wouldn’t let me proceed. I checked the tracking number, and it indicates that the package was "delivered to the recipient," but I'm completely in the dark about who that might be. I usually need a delivery code, but I didn't receive any calls, and I never provided a code. It is completely unacceptable for a courier company to manage deliveries in such a careless manner and disregard their customers. I need this issue addressed right away. I'm trying to track my package, but it says it was delivered to someone else. Can you help me understand what's going on? I really hope to avoid experiencing such inadequate service in the future.