Turkish Airlines Flight Denial After Payment

On September 15, 2023, I booked a flight from Istanbul (IST) to Paris (CDG) for December 26, 2023, and a return flight from Paris (CDG) to Istanbul (IST). As always, I chose Turkish Airlines to be part of their loyalty program. This special trip was to celebrate my wedding anniversary with my spouse. Due to my job, I frequently fly to Vienna, and on December 11, 2023, I had to go to Vienna for a business trip. Despite more affordable ticket options, I chose Turkish Airlines for their loyalty program and trusted quality. Due to extended work in Vienna, I couldn't join the Paris trip on December 22, and my spouse traveled alone. I joined her in Paris from Vienna, and we celebrated our wedding anniversary. However, for the return flight, I couldn't complete my online check-in while I could for my spouse. I spent the last day of my vacation on a lengthy phone call with a customer service representative who lacked sufficient information. As a result, I was denied boarding on the prepaid flight because I missed the first leg, while my spouse was allowed. At the last minute, Turkish Airlines sold me a new ticket for 15,000 miles and €90. My last vacation day was emotionally ruined, and my trust in Turkish Airlines was shattered. I have since booked a ticket with Pegasus for the Cologne fair on January 13. Due to this unfairness and inconvenience, I no longer purchase tickets from Turkish Airlines. I demand a refund of my miles and the €90 payment, as well as compensation for wasting the last day of my vacation. If I do not receive a satisfactory response from Turkish Airlines, I will escalate this issue to the highest level, bypassing intermediate management. I will also voice my concerns on Twitter and other social media channels. Despite previously receiving quick responses to feedback, I have yet to receive a reply to my second feedback on this matter.