Turkish Airlines Damaged Cabin Baggage Compensation Issue

On December 9, 2023, my baggage was seriously damaged. At the Turkish Airlines baggage section, as there was no suitable cabin baggage available, a 'Damage Report' was created. They personally took a photo of the damaged suitcase with the reference number ISTTK60271/09DEC23/1829GMT, and recorded my details by taking copies of the baggage tag, ticket, and passport. Later, they gave me a paper to follow up on the incident and obtain detailed information. Despite a few days passing, no one contacted me, so I reported my complaint again to the place mentioned on the paper. After about three months, when I checked the website due to not receiving any response, I saw that the process was not completed due to missing documents. On March 8, 2024, I re-uploaded the documents previously taken by Turkish Airlines. For the suitcase I bought in 2022 for ₺1,600 and used with great satisfaction, I was offered ₺1,120. I accepted this offer through the system and submitted my complaint. I am curious how a suitcase I bought for ₺1,600 in 2022 is valued at ₺1,120 in 2024. The suitcase had separate compartments for liquids and various features. It was not an ordinary cabin baggage. Despite explaining this to both Turkish Airlines officials and the insurance, I am curious about how this amount was determined. I express my dissatisfaction with the amount offered and request the necessary actions to be taken.