Xiaomi India — mi note 7 pro network issue

Address:

Sirvi complex,Plot no-17,Flat no-303,Kamothe sector-21,opp to Yashoda Hospital, Mumbai City, Maharashtra, 410206

My name hemkalyan pal
I purchase phone 14.06.2019
4-5 times visit service center panvel mumbai
1st time software update
2nd time format
3rd time antina change & also change sim card
4th time software upgrade to latest software 11
5th time service center not solve my problem.
But problem still today 29.12.2019
There are network issues in redmi note 7 pro, it happens 3-4 times a day, whenever i try to call someone the call cannot connects to fix this everytime i have to reboot my phone.
Another issue is no sim card issue, i have both the sim in my phone but it shows no sim card automatically sometimes, and i have to reboot my phone to fix this issue.
Another issue is sometimes anyone who is calling says that my phone was switched off, but it doesn't.