Turkish Airlines Flight Seat Change Without Notice

We had a flight with Turkish Airlines from Istanbul to Kayseri on July 22, 2024, flight number TK2010, scheduled to depart at 6:35. We checked in 24 hours in advance and were assigned seats 10a and 10b for me and my spouse. However, upon arriving at the airport, we were informed that our seat numbers had been changed to 11d and 11e. The reason given was that our seats were allocated to a family with a child. Shouldn't we have been informed about this change? The so-called child in the family was 15 years old. The website states that no changes can be made after the boarding pass is issued. We can't make changes, but Turkish Airlines changes seats as they please. The cabin crew and ground staff told us in an unprofessional manner to complain to customer service. They did not assist us. A company like Turkish Airlines, which serves globally, making such unauthorized seat changes has caused us inconvenience. We urgently request that this issue be addressed.