Vodacom Centurion Service is ****

This is my second complain regarding vodacom's poor service. I bought a Sony Experia E4 from them on 10/06/2015. After I've had the phone for 6 months it started giving me problems. I took it in for the first time on 07/01/2016 for a speaker problem, it came back on 14/01/2016. I returned it on 03/02/2016 for the same problem. They brought it back on 16/02/2016. I took it back on 18/02/2016 because it was not charging. This is when they took it for 6 weeks with no communication. That is when i first wrote to Hello Peter. I asked for an exchange from Vodacom since their device was faulty and was not taken seriously. On 22/03/2016 I took it in as it just switched itself off and did not charge. Its been there till today. Last week Friday I was called to come and fetch my phone as thee is nothing wrong with it. I then asked why they took it in if there is nothing wrong with it. Are they waiting for my 1yr warranty to expire so that they are not liable. I have asked for an exchange and their response is that a request has been submitted. I am a free lance artist and rely on my phone for bookings and this has all been explained to vodacom but they just don't care.