Zara Refunds Did Not Reach My Card

I am reaching out to address an ongoing issue with two refund transactions that have not yet been credited back to my card, despite a significant amount of time passing. The first is a refund of ₺1,490 from ZARA dated May 22, 2025, and the second is a refund of ₺2,998 from H&M dated May 15, 2025. Even though both brands assert that the refunds have been completed, I still haven't received either amount. H&M indicated that the refund did not go through on their side due to "operational reasons" and noted the involvement of Iyzico as a payment intermediary. Despite my requests, they declined to offer any practical assistance, stating that I am not allowed to reach out to Iyzico directly and that they are also unable to pursue the matter any further. ZARA, however, claims that the refund has been processed and has closed the case without providing any additional details. Both transactions were completed with a Denizbank prepaid virtual card. I reached out to Denizbank, and they assured me that there are no refund transactions showing in their system. They recommended that I proceed with a chargeback. Regrettably, the "Transaction Dispute" section on Denizbank’s website does not accommodate submissions for prepaid virtual cards, which leaves me without a means to move forward. This issue has resulted in a financial setback of around ₺4,488, and it has been almost a month without any resolution. I kindly ask for: (1) an immediate refund of the outstanding amounts, or (2) a clear, documented statement confirming that the refunds were successfully processed, and (3) guidance or assistance in submitting a chargeback for prepaid cards. If this issue isn't addressed quickly, I will take further action by bringing it to the Consumer Arbitration Committee and exploring all legal options at my disposal. I appreciate your attention and would greatly value your swift assistance.