Pep cell sold me a broken phone

Pep Cell in Pretoria station square, I bought a phone 3 weeks later there was no network on the phone. I took it to shop, they took it for 7 weeks. It came back still no network. I told them and manager told she does not fix phones. I explained that i need this phone working by 6th November because I am leaving Gautang to KZN i am not coming back. She said it not her problem. I told her i have came twice to the shop and i am using petrol of R300 to come. She said what that have to do with her. I told them to give me another phone, she said she can't. Now I will be leaving on Saturday i will never get my phone back.