LG Electronics — oled television not working

My oled tv model 55 sec 930 purchased on 22nd sept 2016, about two months back developed a problem of audio on but no video.in response to my complaint the service center is supposed to have repaired/replaced the panel/screen. It worked fine for a few days but again went dead, this time also the audio. A fresh complaint later the service engineer replaced the mother board but it developed a fault instantly and i was told the supply board has also to be replaced. A new set of these boards were tried out but it still didn't work. The status as of today is that the latest complaint no. Rnp[protected] dated 12/09/17 is pending and i am without a tv. Please intervene for a speedy resolution.
Regards