Sony Xperia Z2 problem phone

I bought a contract for a Xperia Z2 in June 2014, in December 2014 while on holiday in South America the caller on the other end could not hear what was being said. When I returned home the problem still persisted. I took it to the MTN shop when I return in January for repairs,however the problem was not fixed and had to be booked in for repairs a second time. During the second repair I received a notification that my phone will cost approximately R4400.00 to repair. <br> I conducted some online research [URL Removed]