Southwind Airlines Damaged My Luggage Beyond Use on Moscow to Antalya Flight

On January 16, I experienced serious baggage damage and related hardship on my Southwind Airlines flight 2S002 from Moscow Sheremetyevo Airport (SVO) to Antalya Airport (AYT). My name is M*** E***, my PNR is R1YA9Y, and my seat number was 22C. Upon arrival at Antalya Airport, I discovered that the suitcase I received had two wheels completely broken, significant structural damage to the body, and an opened zipper. The suitcase could not be transported safely and had become completely unusable. As a result, I had difficulty carrying it, there was a risk of my belongings spilling out, and I suffered direct inconvenience both at the airport and afterward. I immediately reported the situation to the Lost Baggage Office at Antalya Airport, where a Property Irregularity Report (PIR) was created, and photos of the damage were attached to both the report and my claim. This was not a minor cosmetic issue but a case where the baggage had entirely lost its functionality, which is why I do not find repair to be an acceptable solution. I purchased the suitcase approximately three years ago and no longer have the receipt; however, under the Montreal Convention, the airline is obligated to return checked baggage in a safe and usable condition, and my inability to provide an invoice should not eliminate my right to compensation. Accordingly, I am requesting compensation of $150, which reflects the current market replacement value of my unusable suitcase. In addition, although my ticket included a 10 kg baggage allowance, I attempted to purchase additional baggage in advance through the Southwind Airlines website, but the system repeatedly gave errors. Because there was no live support available and it was not possible to reach Turkish customer service while I was in Russia, I was unable to get assistance. As a result, during check-in at Sheremetyevo Airport, I was charged 5,175 rub for my total baggage weight of 18.9 kg, meaning 8.9 kg excess. My inability to purchase extra baggage online was entirely due to a technical and service-related failure, and applying the more expensive airport baggage fee caused me direct financial loss. For this reason, I am requesting a full refund of the 5,175 rub excess baggage charge, or at minimum a refund of the difference between the online baggage price and the airport price. In light of all these issues, I am requesting compensation of $150 for my unusable suitcase and a refund of the 5,175 rub excess baggage fee charged due to service failure. Even though two days have passed since the incident, I have not received any satisfactory response, and I respectfully request that my claim be reviewed in writing and that I be informed in writing within a reasonable timeframe.