Bad Service From MTN & False Advertising From SONY

I HAD UPGRADED MY CONTRACT WITH MTN (FESTIVAL MALL BRANCH) WITH A SONY XPERIA Z. 3 WEEKS AGO, THE PHONE REFUSED TO SWITCH ON SO I HAD RETURNED THE DEVICE-15/02/2015,THE AGENT ASSESSED THE PHONE & IN DOING SO, SHE HAD REMOVED THE SCREEN PROTECTERS WHICH I HAD PURCHASED, OUT OF MY OWN POCKET & WHEN I HAD ASKED IF THIS WILL BE REPLACED, I WAS INFORMED THAT THIS IS PROCEDURE IN ASSESSING THE PHONE & THEY WOULD PUT BACK THE ONES THAT WERE TAKEN OFF. THIS IS UNACCEPTABLE, AS ONCE SCREEN PROTECTERS ARE REMOVED, IT CANNOT BE PLACED BACK DUE TO IT BRINGING UP AIR BUBBLES & NOT BEING ABLE TO FIT BACK PROPERLY. I WAS ALSO EXPLAINED ON THE FEES THAT WOULD BE CHARGED, THIS PHONE HAS A WATER RESITANT FEATURE & THE AGENT ADVISED THAT I WOULD BE CHARGED SHOULD THERE BE LIQUID DAMAGE ?! I FOUND THIS VERY STUPID & DISPLEASING AS I PURCHASED THE DEVICE DUE TO THE FEATURES UNLESS THIS IS FALSE ADVERTISING FROM SONY?! AFTER THIS EXPERIENCE , I WILL NEVER PURCHASE ANOTHER SONY DEVICE AGAIN & I WILL ALSO NOT RENEW MY CONTRACT WITH MTN(BEING A VALUED CUSTOMER FOR A LONG PERIOD OF TIME) AS THE SERVICE I HAD RECEIVED WAS A \DO NOT CARE ATTITUDE". TIL TODAY"