Nissa Car Rental Deposit Not Refunded After Vehicle Return

I rented a Fiat from Nissa at Izmir Airport in Turkey and paid a security deposit of €500 on April 20, 2026. The lease ended on April 23, 2026, but despite this, my security deposit has still not been refunded. Since the end of the lease, I have contacted Nissa several times. Each time I was given a different explanation, such as that the banks were closed or that the deposit would be returned within the week. However, none of these promises have been fulfilled and the €500 has still not been transferred back to me, even though I have all the rental documents and confirmations. I request the immediate full refund of my €500 security deposit without any further delay.