Vodacom Samsung S5 faulty screen mirror function

I renewed my Vodacom contract (for my mother) on 2 April 2015 and decided on the Samsung Galaxy S5 phone specifically for the screen mirroring function (sales consultant confirmed that this S5 would connect to any Samsung smart TV). I then bought a Samsung smart television LED40 model in order to watch phone photos on the new television. The S5 phone failed to connect to the television, however the television connected perfectly with the AVTV sales consultant's older Samsung phone and various other Samsung phones. The phone was subsequently booked in 3x at Vodacom and once at Samsung. Apparently (per repair consultants) the Vodacom S5 phone batch has a defect with regards to the screen mirror function - however, Vodacom refuses to replace the phone with one that can do screen mirroring (as advertised). The repair consultants has in writing referred me to sort out the problem with Samsung as they claim that there is a problem with the Samsung Galaxy S5 batch provided to Vodacom by Samsung in terms of screen mirroring. This is unacceptable. My contract is with Vodacom. After more than 6 weeks of booking the phone in and out of various repair centres I have had enough!