Poor service in the Samsung Mall of Africa

Samsung (Mall of Africa) I am very disappointed with service received in your store. I bought a screen guard for my Samsung S7 and one of your staff members installed it for me. The very next day I returned to complain that it is clearly pealing off, which I was informed is part of the warranty (should this happen I can bring it back). I had also observed the strict instructions the staff member told me; not to put it in the cover over night so the screen guard settles properly. I did not use the phone the whole of Friday evening after installation and when I returned the next day, I was turned away. I was very disappointed because this does not align with your value of Excellence. Please may you sort this out?