Faulty IPhone purchased

I upgraded in December 2015 for an iPhone 6 and a month later experienced problems with battery. Went to Vodacom for assistance as I did not expect to have any problems with any product from a well respected company such as Apple. I was merely told that the phone had to go in for repairs that is all. I have not sent the phone in and I am very upset as I expected better service. After numerous emails to Vodacom customer service and Apple themselves and two months later I am still sitting with a brand new iPhone 6 which has a faulty battery.