Paying for a contract phone that constantly breaks

My wife and I took out a Vodacom Flexi 200 contract from Autopage Herm****, with the Sony Xperia M4 Aqua as the chosen device. 2 Months After taking delivery of the device, the microphone stopped working. I took the liberty of reading up on the device, and quickly found out this particular phone was prone to software faults, and that there were masses of unhappy customers around. An employee of Vodacom Herm**** even told me, that they would not recommend the phone to anyone as they were very prone to problems. I took the phone back to Autopage, where I was told that the phone would be sent to be be assessed in JHB, and that they would send me a new phone (same model). I was not too happy with this, considering what I now knew about the handset, but felt that I should give it another go. Nearly 3 weeks later, I received a new replacement phone, which 2 months later also started giving problems. This phones camera flash stopped working and it heats up during normal use. Again, I went back to Autopage, and again I was told that the phone would be sent away. Another 2-3 weeks without a phone, and now my 6 months contract warranty is nearly done, which means that I am stuck. Terrible.<br>