Xiaomi India — Mi note 3 not working after 2 months of purchasing

Address:	New Delhi, Delhi, 110088
Website:	www.mi.com

I heared a lot about MI phones, that they are very good at low price, having very good features and all. But for me, it is a very bad experience with MI. I purchased MI note 3 in June, but after 2 months I am very much frustated. It is not working properly, It gets Auto power off and take approx 5-6 hours to switched on, and sometimes a day even. I also given it to service center approx 1 month ago. They gave back to me after updating software next day, but same issue again. Then again I submit it, they told that it will take 10 days to repair. And now its almost a month they did not repaired it yet, nor they provide any info about it, how much will it take. I call them again and again, but no response from their side. Kindly help me regarding this. My SN no. Is 12665/20234837 I purchased this from your MI.com site, and it has warranty period of 1 year too. Please revert asap.