Faulty, overheating Samsung S6 Edge

My name is Joan Letlotlo. I purchased a Samsung S6 Edge 64GB on 8 September 2015. Nearly 2 weeks after that it started overheating and the operating syste4m was not working as effectively as it used to. I took to to several Vodashops and the detected nothing wrong with it. I then took it to the Vodashop at Ghandi Square and they booked it in for repairs about 2 weeks ago and it was taken to Fourways to be repaired. I got the phone back last week Wednesday and to my surprise it still has the4 same problem. I called the repairs department on *** and the said I have to take it in for repairs again. Now this is a huge inconvenience for me to be without this phone. Why was the handset not fixed properly the first time? I want one of 2 things from Vodacom and nothing else. 1) Vodacom has to issue me with a new handset, where I can got to the Vodashop at Ghandhi Square as its convenient for me so that I can get the handset immediately OR 2) Vodacom comes and collects the handset and cancel the contract. I will not have this. This is an indication that Vodacom sold me a handset that is faulty and it should be replaced with immediate effect.