Turkish Airlines Deleted Seat Reservation

I am writing to report a problem with my Turkish Airlines business class booking on flight TK39 on 28.03.2026. When I booked this flight in January, seat selection in business class was included, and we carefully chose and reserved seats 4K and 5K, specifically next to the window and directly one behind the other so that we could sit close together. This flight is our honeymoon flight, so having these specific seats was especially important for us. On 09.03 there was a schedule change on our second connecting flight from Istanbul to Frankfurt, while flight TK39 itself remained unchanged. After Turkish Airlines changed only the time of this second flight, all our previously reserved business class seats 4K and 5K on TK39 were deleted from the booking. We only realized today that the schedule change of the second flight led to the loss of our seat reservations on TK39. When we checked the seat map, we saw that these seats were no longer available and that only three other business class seats were free, none of them next to each other or matching what we originally selected. When we called Turkish Airlines, we were informed that our reserved seats had been given to other passengers and that nothing could be done to help us. I find it unacceptable that a time change on a different connecting flight automatically deletes confirmed business class seat reservations on TK39, especially on a honeymoon flight, without any effective solution being offered. My clear expectation is that Turkish Airlines restores the seat reservations 4K and 5K that we made in January for TK39 on 28.03.2026, or, if that is technically impossible, provides equivalent or better window seats close to each other, similar to our original seating arrangement, so that we can travel together as planned.