Sick and Tired of the issues with Vodacom and their device

I have had to book my device in at Vodacom Canal Walk Shopping Centre technical dept on two separate occasions because of an APP error I have been getting. Bear in mind that this device is not even 2 months old yet and conveniently only started giving issues once out of the 7 day return period and has been booked in twice already. The last time I booked this device in I made it VERY CLEAR that I did not want this same device back because this is the second time its booked in for the same issue and there is ZERO guarantee that this wont happen again... AND HERE WE ARE YET AGAIN. I just received my device back last Saturday and the same issue persists.. Vodacom Canal Walk Shopping Centre REFUSED to motivate for a new device by saying that the device was tested and there is nothing wrong with it, it was merely a setting on the device that needed to be changed. So what now??? the setting has been changed AND STILL its happening! Quite frankly the Store Manager, Pierre simply agreed to do so in order to shut me up. I have been given the run around by Vodacom Canal Walk Shopping Centre since day one. They have done absolutely nothing to compensate me for the inconvenience of having to sit without a phone every time despite, petrol, time and energy wasted driving back and forth despite claiming to do so.....Data never receive, that was a lie...among other lies. The agents who call say things just to make it seem as if Vodacom cares when in actual fact there is no follow through and no consideration for the customers. Vodacom Canal Walk Shopping Centre was very quick to make a sale but useless at after sales customer service. USELESS!!!! I have 2 contracts with Vodacom, I want both contracts cancelled because quite frankly I refuse to pay for something that is not working optimally. I have been inconvenienced one too many times by Vodacom and specifically Vodacom Canal Walk Shopping Centre. I have literally had it with this entire situation. Time for talking is over so don't bother! I will take this further legally.