GAP Canceled My Discounted Order

On November 24, during a discount offer on Hepsiburada, I ordered a bomber jacket from GAP with a 30% discount. On December 1, I received information that the order was not available and had been canceled, with a refund to be issued. Why is a product not in stock during the discount period being offered for sale? We chose GAP because the discounts were only valid for a short time, and now GAP has canceled the order, taking away our discount. The same product is still being sold on their own website. I request a refund of the GAP discount. The faulty inventory management has led to disappointing consequences for my purchase decision and has affected my trust in shopping at GAP.