Xiaomi India — about sim slot

Address:	Mumbai City, Maharashtra, 400058
Website:	Mi store

Hello,
I had bought redmi note 4, and i am facing an issue with the calls i. E network problem. I have a vodafone sim and it doesn't work it show no network or very low range where in you can't here any voice of the person on the other side, so i tried with other sim cards for eg. Airtel, even it din't worked (Airtel sim dint even showed up any network. Zero netwrk.
I guess it's the issue with the sim slot or may be sound i don't know exactly. But i need you to work on it or try and exchange my phone with some other model.