Request for 'No Show Document' from Turkish Airlines for the Missed Flight

Dear Sir/Madam, I submitted the following request to customer service:
''On February 27, 2024, we had a flight from Istanbul to Adnan Menderes with the code V27PVA for two people. Due to reasons caused by the travel company, we could not board our flight, and our tickets were forfeited. We purchased new tickets and flew on March 1, 2024, with the code SGY8C7. The travel company will compensate for the missed flight. For this, they require a document proving that we did not take the flight on February 27 and did not receive a refund for the ticket.''
In response, I received the message: ''We have determined that you completed your outbound flight and completed the refund process for your return flight.'' There is no issue with our outbound flight. We missed our return flight. Since our ticket was non-refundable, we only received a payment of 128₺. I am not requesting any money from Turkish Airlines. I only need a document proving that we did not take the flight and did not receive a refund for the ticket. Despite repeatedly applying through Turkish Airlines' feedback system, I always receive similar responses. I kindly request your assistance.
Sincerely.