I am yet to Receive the Refund that Trendyol Sent to My Old IBAN

What seems like an eternity ago, I purchased a headset from Trendyol. I sent it to the warranty because the headset's sound was muted. I took them up on their offer of a warranty refund. I sent the product to Trendyol because they told me to. We approved the transaction and refunded the money. Unfortunately, my IBAN has changed since I purchased that product, and a lot of time has gone by. I tried to explain my issue to three separate customer service representatives, but they all failed. While they claim it will take 2-10 business days, I've seen it arrive in as little as 1 or 2 days. My funds have still not been received after a week. Even though they still say "your money will come," my IBAN has changed due to my explanation. What makes you think that funds sent to an unregistered IBAN will actually arrive? There's no use in contacting Trendyol's live support.