Tommy Hilfiger Store Applied 10% Instead of 25% Discount

On Sunday, 19 April, I purchased a knit sweater from the Tommy Hilfiger store in Bursa Korupark AVM within the scope of a campaign. The price tag of the product was ₺7,699. When the discount was applied at the checkout and I checked the receipt, I noticed that the discount was only 10% instead of the promised 25%, and I had paid ₺6,929.10 for the product. There were also posters inside the store clearly stating that a 25% discount would be applied on the first purchase. After noticing the situation, I shared the receipt images and my phone number with the store so that I could be informed about the issue, but I have not received any response in 10 days. The store does not answer the phone, and I also do not receive any reply to the emails I send to customer service. I made the payment for the sweater by credit card. I request that the campaign conditions promised in the store be fulfilled and that a 25% discount be applied to the product as stated, and that the difference between the amount I paid and the correct discounted price be refunded to me.