Vodacom false 7 days replacement policy

Upgrade to the Samsung S6 in May on day 4 the phone died in the middle of a call with 60% power, tried to recharge the phone with all the chargers in my house including the charger I had gotten with the WIFI I had acquired on the same day with the phone with no joy. On day 5 took the phone back to Vodacom. They took the phone in & repaired it I was told they were not going to give me a new phone as I had brought in the box the WIFI charger & moreover they had fixed it.This is not what the policy says I was supposed to be given a new phone seeing the phone died within the 7days.And now this phone does not work I have no network all the time data hardly works I took it in to Vodacom on the 16th June they want me to send the phone for repairs. My issues is this phone has been faulty from day one & Vodacom does not want to give me a working phone according to their policy I should have been given a new phone if it was not just marketing gimmick to get customers hooked. This phone is not 2 months old and yet it needs repairs for the 2nd time in a month that's unacceptable given that I have been a Vodacom customer for more than 10 continuous years. CAN SOMEONE PLEASE ASSIST ME!!!!!!