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

First of all, I am writing this complaint because I have never encountered a more indifferent, irresponsible, and unresponsive courier company than yours. I would like to complain about your Köseköy/Kartepe/KOCAELİ branch for not answering calls and working irresponsibly. We purchase products by paying fees and entrust them to you. If we cannot receive them properly or find out where they are, what business do you have in this sector? Please take the necessary action. I am complaining about your Köseköy branch, the Köseköy branch manager, your general customer service, and your system. My package, with tracking number 31130255039177, has been marked as delivered in your system, even though it has not been delivered to me. When I contact your customer representatives, they constantly mention that there is an issue with your system and that they cannot access it. If this product does not reach me, I will seek my rights through legal means. I expect the necessary actions to be taken as quickly as possible.