Turkish Airlines Ticket Refund Issues

I purchased a round-trip ticket to Cyprus from Turkish Airlines using my mother's card, and I was told she needed to be present. However, there was no prior notification about this requirement. I already faced issues during the check-in and boarding pass creation processes before the flight. They told me I could resolve it at the airport. At the airport, they informed me that the cardholder must be present, otherwise, the ticket would be forfeited. Since the cardholder was out of town, I couldn't comply and requested to show the card via phone, which they refused. As a result, the ₺7000 round-trip ticket was forfeited, and I had to buy a new ticket for ₺9000. I was advised to apply for a refund, which I did three times, but now they are rejecting it. Due to their inconsistent guidance, I suffered a loss of ₺7000. If they had informed me during online check-in and allowed a refund, this issue could have been avoided. The incorrect information and guidance caused my inconvenience.