Samsung ADH and head office refuse to help

I bought my Samsung S6 Edge in October 2015, and it has not given me one day of pleasure. It gets warm the battery last for max 4 hours. I loose signal, It randomly switches of and I can connect to wifi and must constantly restart my device. I have been at 3 of my network stores it has been at ADH and Samsung. They all refuse to replace it or resolve the problem. Its such poor service. This device is 4 months old. I have never had such poor service from Samsung in my life, I demand service Samsung is suppose to be a leading brand with top service. I want Samsung to contact me and to resolve my issues. I am a business woman my phone is my business I can't be without it. And I am loosing out on business due to this.