Turkish Airlines Did Not Pay My Refund

I purchased a ticket from Turkish Airlines on 03.08.2023 for 3300₺ and canceled it on the same day. They refunded the amount, but I had opted for installment payments through my bank. Although the total amount appears refunded and neutralized, my installments are still being charged. Turkish Airlines informed me that the refund of installments would be processed in installments, but I confirmed with my bank that the refunds had not been made. The bank told me that the money was requested by Turkish Airlines, which is why it was paid, but Turkish Airlines continues to charge the installments. Essentially, I am still paying 3300₺ for a canceled ticket. Despite submitting feedback forms twice, they simply look at the refunded amount and claim they have refunded it. Yes, you refunded the total amount, but since the installments continue to be charged, it goes back to negative. I provided the reservation number and approval code from the bank and wrote again. Now there is no response. It's been two months, and Turkish Airlines still hasn't resolved my issue.