Turkish Airlines Customer Service's Irresponsibility

We called Turkish Airlines customer service to travel from Buenos Aires to Istanbul Airport with two adults and a cat. Just before purchasing the ticket, we spoke with a customer representative who confirmed that there was space for the cat on the plane. Within a minute, we put the lady on hold, purchased the ticket, and then the representative told us there was no space for the cat. The phone conversation was recorded by both Turkish Airlines and us. The call took place on March 6th around 19:24 via the number 0554********15. Despite our inconvenience with the ticket reservation, the representative refused to change and did not assist in any way. She provoked us in our distressed situation by saying, 'Complain wherever you want.' Therefore, we request the necessary actions to be taken, our ticket date to be moved to the next available date, and we want to file a complaint against the customer representative. Other necessary complaints have also been made to official institutions.