Cell phone upgrade

I upgrade my line ***on 12 September 2015 at Game in Worcestor and got a Samsung Core Neo zero plus phone. The phone just work for twelve days and it starts to gave problems. We gave it back to Game in Worcestor and they send it to Vodacom repairs in Cape Town. After a full three weeks we asked where are the phone and they received it the next day from the repair shop. After receiving the phone, the phone was still not working because it does not read the sim card. I did go to the Vodacom shop in Worcestor again and they test it also and they took it in again for repairs and send it to the Vodacom repairs in Cape Town with job number ***2. Its now two weeks and i have not heard from them. From the 12 September i had upgrade, i just had the use of the phone for twelve days, its all together now for five weeks in the repairs shop and i still had to pay my contract monthly but i do not get any value for my money i had to pay at Vodacom. I do not want to get back my cell phone what they gave me, i want a new one in its place because i dont want to pay for one who has just work for twelve days and spend five weeks in the repair shop, who knows how many times it will go bac