Deichmann's Faulty Shoes, Poor Service, and Rights Denied

I bought two pairs of the same item from Deichmann, one in size 40 and one in size 41, but both developed spontaneous openings around the shoe. I dropped off the two shoes at the Deichmann store in 41Burda for repairs on May 19, 2023. I went to the store on June 2, 2023, after receiving a message stating that I could replace the examined product with a new one. They informed me that they did not have the product in stock and that I would have to pay the price difference if I wanted a new one. I did not return the product for an exchange or refund; instead, I returned it for repairs. Even if repairs were not possible, a new pair of shoes should have been provided because defective goods must be compensated in kind. I noticed that the prices of all the shoes in the store had risen, which added to my anxiety. I contacted customer service and explained the situation, but they declined to assist. If repairs were not possible, I suggested that they should have informed me and arranged for the product to be returned to my address. They, however, rudely responded, stating that they do not operate in this manner. I gave my shoes to be repaired and expect to receive a replacement pair, whether repaired or new. Despite obvious product flaws, they treat me as if I'm in the wrong. They should compensate me appropriately for the shoes. If they do not assist me with a new pair or repairs, I will exercise my legal rights and file appropriate complaints with the appropriate authorities. Customers are being upset because they are mishandling these situations. They accept the shoes for repairs and then issue refunds, claiming that the products are not repairable, and when customers choose new products, they charge the price difference, effectively making a second sale.