DEFECTIVE TV - WANT TV REPLACED

I PURCHASED A TV FROM BEARS AMANZIMTOTI IN SEPTEMBER 2013. ( SAMSUNG PLASMA , 51 INCH), THE TV AS GONE TO THE TECHNICIAN 2 TIMES WITH THE SAME PROBLEM . WEN YOU SWITCH THE TV ON, THE SCREEN IS BLANK. THE TV HAS TO BE SWITCHED OFF AND THEN ON. NOW I CANNOT EVEN CONTACT THE STORE TO COMPLAIN THE 3RD TIME AS THE NUMBERS DO NOT EXIST. I WAS TOLD THAT IF AN APPLIANCE GOES TO A TECHNICIAN 3 TIMES WITH THE SAME PROBLEM , THE TV WILL BE REPLACED.. I AM NOW REALLY FRUSTRATED AND I WANT THE TV UNIT TO BE REPLACED.