Turkish Airlines Price Lock Issue with My Booking

On August 30th, I made a reservation with THY for two people for the routes Izmir-Washington on March 9, 2024, and Los Angeles-Izmir on March 22, 2024, with a 15-day price lock option, totaling ₺47,400. I paid ₺5,300 for this reservation. According to the terms, if I ticketed within 15 days, the ₺5,300 I paid would be refunded. The deadline was September 14th at 14:09. Despite trying from 8 AM on September 14th both via the website and the mobile app, I couldn't purchase the tickets. When I tried on the website, I could see the reservation but there was no button to make a payment. When I tried on the mobile app, I received a warning saying, 'Your transaction could not be completed because the price information could not be displayed. Please try again later' when I clicked on Pay&Fly. I contacted THY customer service at 0850 333 08 49 at the following times regarding this issue:

08:46 - 9 minutes
12:53 - 10 minutes
13:18 - 10 minutes
13:47 - 14 minutes

During the first call, the representative said they had emailed the relevant department and took my number, promising to call me back. In the second call, I was told to contact an insurance company named Xcover. In the third call, another representative said they had emailed the relevant department with an urgent code and would call me back. During the fourth call, the representative tried all options until the end of the purchase option period and said they could only define a ticket for ₺67,000 instead of the ₺47,400 I had locked in. They offered to process the payment at this new price, which I declined. The representative then advised me to create a feedback report via the THY website, stating there was nothing more they could do. I submitted my feedback just a few minutes before the deadline of 14:09. After the deadline passed, I checked my reservation on the THY website and saw that it was no longer visible and had been canceled, meaning the ₺5,300 I paid for the price lock was wasted. I have never experienced such bad faith in my life. I am attaching relevant screenshots to this complaint. My reservation code for the 15-day price lock, which is no longer visible, is r***yi; my feedback tracking code is 9394***. I have purchased new tickets for the same dates and routes, paying a total of ₺47,700, not the ₺67,700 the representative mentioned. I am requesting a refund of my ₺5,300, and I am prepared to take legal action if necessary.