Bad Repair with no response

I signed a new contract with vodacom for a Sony Xperia M4 Aqua on the 06-07-2015, received the phone 31-07-2015, after a while I discovered a bulge in the back cover, I handed the phone in on 28-09-2015 at my Vodacom dealer and got it back 04-11-2015 with the exact same bulge after I was assured by the vodacom advanced repair center that they had replaced the back cover and made adjustments, as stated in the job card that came back with the phone.<br> <br> I phoned the Repair center again, they told me to return the phone, I asked for an alternative seeing that the phone will be away for another month if I had to send it back, they gave me the email address to the Repairs Escalation [Email Removed] which I emailed with no response.