Selling 3rd party accessories as original

I bought a flip cover for Samsung Note 4. I asked for original cover so i took it that the one they sold me was a original. After 3 months having the cover i noticed the cover was shaving marks on the screen. I then went to Samsung because it was a original cover and also the note 4's screen wasn't suppose to scratch. After taking it to Samsung they told me that the cover wasn't original and it was a 3rd party cover and that they are refusing replacing the screen under warranty. I then went to Vodacom Randfontein and spoke to the manager .She refused to believe that the cover they sold me was a 3rd party cover and kept on saying that it was a original Samsung cover.Well Samsung told me that all original covers are branded Samsung and this one was branded Muvit. You could c where the pouch was shaving on the screen.It had marks exactly where the cover had a insert on it. She then cleaned the screen and said \ you c