No spares for new phone

I have upgraded my contract with vodacom and received a new Sony Z3 phone. I had the phone for 3 weeks and there was a problem with the phone because the screen was going on and off. We handed in the phone to the vodacom repair shop in Pretoria city. We received a job number ***2. We phoned to hear what is going on and after 3 weeks of constantly phoning they told me there is no spares in south Africa to fix my phone. This is unacceptable for it is a brand new phone. If vodacom can't fix my phone, they must replace it.