Day light Robery

I bought a phone at pick n pay retailers and a few weeks later it started freezing , I sent in the phone for repairs but to my suprise I was rejected apparently because I has a scratch on the screen, I went back to pick n pay mams mall to my surprise the phone has no scratch so they telling me the issue is with mtn here I stuck with a 4 month phone that I cannot use , both pick my pay and mtn are giving me storie , this is pathetic service from both parties