Turkish Airlines Ticket Change - Communication Issue - Visa Rejection

I purchased a ticket for Italy, Rome with a departure on November 14 and return on November 19. I bought my ticket as changeable for visa procedures. My visa was rejected. Due to reasons beyond my control, I won't be able to go to Italy and requested a ticket change for a different country. However, they asked me to pay the difference for the new country ticket as if I didn't have the Italy ticket. They said it is calculated based on kilometers. Why is this information not provided upfront? My ticket is useless, and I can't get a visa for Italy again anytime soon. You say there is only a change fee for the new destination, but the criteria for the fee are not detailed. I assumed the difference would be deducted from my ticket price. In this case, my ticket serves no purpose. I provided feedback and requested a refund. I have sent you the document proving my visa rejection and a copy of my ID. Request number: 9645094 Request number: 9645186