False advertising and non-disclosure of the screen protection being of poor quality

I bought a Oppo Reno10 5G plus in Feb 24 - 4 months later the protective layer started to peel off - the Phone cost R21999 and I had a choice between the Samsung S Series and I was shown the Oppo as the latest and best and very good etc. I bought this phone case from Mimosa Mall in Bloemfontein - I went there to explain how come the protective screen starts to peel and I was told that the sales agent should have told me the this is the basic cheapest screen protector, and I was shocked given how much I spend - I am really unhappy, and this was non-disclosure and as the agent should have mentioned this before - I now consider this product not of good quality