Turkish Airlines Pet Reservation Approval Issues

I'm unable to get a reservation approval for my pet from Turkish Airlines. I have repeatedly sent my dog's rabies titer test and vaccination records to the two email addresses they required, but we have received no response at all. Worse yet, our emails are being returned with a message that the recipient's mailbox is full.

We've had to cancel our flight reservations twice because we couldn't add our pet to the booking. It's absurd that such a large company doesn't have a single person to manage and respond to two email addresses. The call center staff are unhelpful and seem to have no authority to resolve anything. Where should we file a complaint to get this issue resolved? What more do you need from us?