POOR SERVICE KLERKSDORP MATLOSANA MALL

My father bought a new Samsung J1 on 17 March 2016 at your branch in Klerksdorp Matlosana mall.When he got home the screen kept flashing,went back the next day (18March 2016) they said he has to just wait a day to see if it changes,it did not.Went back today (19 March 2016) and they refuse to exchange the phone which wasnt working correctly from day one.They have been loyal clients to Cell C for 5 + years and is on pension amd this is how the get treated,all the other service provoders told us that they would exchange it for a new one without any problem.