Unsatisfactory service

first of all let's get one thing straight here I'm paying money. Hard worked money for a phone that hasn't been working since day one that I joined Vodacom .. I purchased a Samsung s4 mini on 19 November 2014... late December we took the phone back in for repairs in richards bay boardwalk branch the phones network settings have been going on and off continuously and have taken the phone back 4 times since and have still not received a phone that works. The 3rd time we handed the phone into vodacom they sent it back 3 weeks later with no battery or back piece that had been handed in with the phone when we gave it in for repairs... All the technical staff at the vodacom branch could only tell us to hand the phone in or send a email but nothing was really been done about the problem... This phone I had purshed for my girlfriend that was in between jobs and needed the phone to get a job but we been struggling ever since with this phone... very unhappy clients with vodacom... btw I have a contract phone with mtn and have not yet once had a problem of any sort with the service provided..