Columbia Sold Me a Defective Coat and Blamed Me for the Zipper Issue

I bought a Columbia coat from Metro Market Büyükçekmece store, a few days later I saw that the zipper was working and when I took it to the store once a week they said they would send the product to the company for inspection and the answer I got was that there was a user error and the fault was still there, it had never been worn and the product was returned within a week, what kind of user could it be, they tried to help the Metro authorized friend by trying something to do, but they were unsuccessful. When I called again a few times, their correspondence did not change and I was directed to take legal action since they had sold me a defective product. I will apply to the Consumer Court as well as write a complaint to the Columbia brand's headquarters in Portland.