Cartier Eyeglasses Screw Cover Falls Off and Store Is Unreachable

On February 2, 2025, we purchased two pairs of Cartier eyeglasses from Gözüm Optik in Üsküdar, Istanbul. One of the pairs I have been using developed a problem when the screw cover on the frame became loose and fell off on its own.
Although I have the original invoice for my purchase, I have tried to contact the store by phone several times to request a paid repair for this part. Unfortunately, I have not received any response whatsoever, and none of my calls have been answered. Since I am currently in a different city, I am also unable to visit the store in person.
My expectation is that the store should stand behind the product it sold and arrange the necessary repair, even if the repair is chargeable. I also expect the store to be more attentive and accessible to customers throughout the repair and support process.