Vodacom
Out of box failure

I upgraded 2 weeks ago, got sony xperia v. The phone worked for about 3 days before starting to randomly switch off. I then took the phone back before the 7 days, of the out of box warranty expired, after waiting more than a week, and speaking to numerous sales staff at tygervalley, the first problem was that the phone was never booked out, and this after a week, something that should take two days to assess problem was and the credit me for a new phone, I went back yesterday and now after almost 2 weeks the out of box failure was rejected, so now vodacom head office is sending back my phone and nothing was done. I find this ridiculous!!!