Turkish Airlines Flight Cancellation Without Notice

We received a message stating that our flights on April 6th from Sabiha Gokcen to Adana, and on April 15th from Adana to Sabiha Gokcen, were canceled. Following this message, we started searching for new flights; however, our attempts through the app and customer service were unsuccessful as all flights were fully booked. This situation caused us significant stress regarding how we would go on our pre-planned holiday. Later, Turkish Airlines refunded us, stating they had no other options due to fully booked flights. We reluctantly accepted this refund.
We were told that the flight cancellation was due to weather conditions. However, when we spoke with customer service, other airlines and passengers flying on the same dates and times reported no such weather issues.
What kind of weather conditions could have occurred on April 5th and 15th that Turkish Airlines canceled our tickets without explanation and disrupted our plans due to fully booked flights?
Having used our annual leave, made our plans, and during a period when people are trying to travel to their hometowns for the holiday, it is unacceptable that our flight was canceled five days prior without notice and without providing an alternative, only a refund. Our priority was to reach our destination, not a refund.
There was no snow, storm, or meteor shower at the specified times. Due to this so-called weather condition, both my family and I are very unhappy and distressed.
We demand that you promptly address this grievance. You owe us an explanation, dear officials. Our flight reservation number is as follows: ttfmnq.