Pathetic, horrible service, it's either they give me a new phone or I want my money back

On Saturday 22 June I went to buy a cellphone at Pepcell in Jabulani, after 2 days the buttons were not working and the WiFi was not working, yesterday I went back there to change the phone since it's was technical errors,there was a lady working there , I explained to her what is wrong with my phone, she just looked at my phone and tell me that I'm dum, there's nothing wrong with my phone! I told her that "Sisi I spent R80 for transport to come and exchange this this phone, I know what am talking about ' she said to me when the phone it's giving me problem, I must take a picture and bring it to her so that she will see" I said aybo I don't have time, cause I'm always busy at work, she said " whenever you've got time just bring it " I asked her what her name since she was not wearing name badge , she said her name is Nthabiseng Makgetla , she's light in complexion, she was very rude and arrogant towards me, even now the phone is giving me problem, what a pathetic, horrible service I've got from Jabulani Mall Pepcell