Unfair Exorbitant Interest Deduction

I am a Yapı Kredi customer and I use a Yapı Kredi World Gold credit card. On my April 2026 statement, an interest charge of ₺13,286.05 was reflected on my card due to a delay of only 7 hours. I misremembered the last payment date because it was constantly changing and, when I realized it, I logged into the mobile application and made the payment on the same day, just a few hours after the deadline. Despite this very short delay, such a high interest charge has caused me serious financial grievance. After noticing the situation, I immediately contacted the bank and requested the cancellation of the exorbitant interest amount of ₺13,286.05 within the scope of customer satisfaction. I have been a Yapı Kredi customer for years and have regularly and punctually paid my card debt. Nevertheless, in the response to my complaint record numbered 16333890, I was informed that the transaction was legal, that the account cut-off and due dates could be changed, and that therefore no refund would be made. To avoid being charged further interest on this already large sum, I paid the full ₺13,286.05, even though I found it unfair. Considering that the delay was only 7 hours and that I have had a clean and regular payment history with your bank for years, I find the interest amount of ₺13,286.05 absolutely disproportionate and unfair. Within the framework of customer satisfaction and goodwill, I request that this interest be fully canceled or at least significantly reduced to a reasonable level and refunded to my card. Otherwise, I am seriously considering closing all my accounts and products with your bank and not recommending Yapı Kredi to people around me.