Heavy delayed on unit swop

After getting my brand new Samsung Galaxy s6 edge from Vodacom, the first issue was that it connectivity issues, but it self resolved after a while. The second issue, and this after just 3 weeks of having the phone, is that the phone started overheating badly. I took it to Samsung(Clearwater Mall) - They said that I should take it to iFix, because its a software problem, iFix said they repaired it, never did told me to take it Samsung Smart Care, they said it would be fixed, but it was never fixed. I told them it was not a software fault, they insisted. After their own investigations they concluded that it was a hardware fault and that I needed a new device. I've been waiting for two weeks to date, they NEVER pick up calls when you try and call the SmartCare center. The issue was escalated to headoffice, but they also never returned my call. I want my phone back, I was not even issued a loan device as interim solution. I am really disappointed, I've always just bought the latest and best Samsung's, but the hardware is failing and the service deliver is failing even more.