HTC — HTC DESIRE 820 getting hang and auto off. Service center not helping properly.

Address:	Gurgaon, Haryana, 122001
Website:	htc.com

My phone HTC desire 820 Getting hang again and again. submitted 3 times in service center (TVS electronics grand mall, near sikanderpur metro station, Gurgaon). Every time they update and return but it doesn't work even a day properly. now they are saying that they will change the main board etc. and it will take 20 more days for getting repaired up. Its been a month already. Either they repair my phone properly or else replace this phone. No benefit of purchasing a phone worth 23000 rupees as it doesn't work for 23 mins even. Have already sent a mail to HTC 5 days before. No reply from them. Just a formal mail mentioning "sorry for the inconvinience". Kindly take the required action. IMEI NUMBER - [protected]