Samsung — TV

My 55 inch TV had a power switch problem. Engineer from Samsung Fracnchisee Cantto International visited and replaced the switch but spoilt the Back Light module and TV became totally black. The TV was fine till replacing the switch. When questioned the engineer of the issue he created, he was rude and informed to complaint to anybody and left post collecting the charges. From past one month i am requesting the Samsung support team to send engineer from some other service franchisee but again and again assigning to the same franchisee and that franchise is cancelling the call. Please help me on this matter,