Apauled by the bad service received

I bought a Samsung J1 Ace at a PEP CELL store in Cape Town on the 21/11/2015 for R1499 cash. Within 2 weeks the phone had software issue which my mother took to a Vodacom repair shop. A month later it had the same problem again and the keypad is not working either. I then took it to Pep cell store in Pretoria Sammy Marks centre, where I was advised to take it to a Vodacom repair shop on the corner of Du Toit street and Francis Baard street. I booked it in and I was advised that they will call me with feedback . In 24hrs I received a call to tell me that the handset will be repaired but I'll be have to pay R1200 because it has electronic and physical damages and the LCD would be changed, which it doesn't and I rejected the quote and I had to pay R57 and had to fetch it. I refuse to pay for a phone which is hardly 3 months old and has never had any physical damages none what so ever, even more pay almost the same amount I bought it. Pep is also passing the buck to Vodacom and also refuses to take the responsibility to have it repaired. As a paying customer who do I turn to because both the retailers are refusing to provide service.