Lenovo — 4g/volte issue on my lenovo z2 plus 32gb black mobile phone

Address:	756001
Website:	[email protected]

Dear sir,
I bought a lenovo z2 plus 32 gb black mobile phone by online on dt. 12.04.2017 which was on warranty period till date. After buying i used jio sim 4g on first slot & bsnl 3g on second slot. After 5 months there was problems in slot 1. Slot 1 not searching 4g/volte network in mobile, but second slot was ok. After that there is no incoming or outgoing calls available in slot 1 in phone. On dt. 30.10.2017 i have updated my phone at balasore, odisha lenovo servicing center. Then its ok for atleast 9-10 days, but after that same problem arises till date.in my mobile no volte/hd network found, so from that date i was facing so many problems. Now i am in tense due to that problem. Now my phone is on warranty period, so please do something. It should be your kindness to me. As lenovo is one of the best brand in india, i choose that mobile. So please look out my matter. Its my humble request to you...
Here, i attached my invoice below...

Thanks,
My contact number: [protected], [protected]