Lee Jeans Gift Card Expired Sooner

Hello, I made a substantial purchase last year at the Lee store in Zeytinburnu Marmara Forum. I was told I had a ₺500 gift card. Unfortunately, when I came to use the gift card, I was informed that it had expired and been canceled due to incorrect information provided by your store. I came all this way and couldn't use the gift card, and no assistance was offered. When I tried to shop online instead, the size I needed wasn't available. Additionally, I didn't appreciate being pressured to buy three items in-store instead of getting the discount for a single item added to the cart. I'm extremely dissatisfied and feel that I've been treated unethically.