Lenovo — Internet activity for Lenovo k3 note mobile.

Address:

Visakhapatnam, Andhra Pradesh

Dear sir, I bought lenovo k3 note through flipcart. the complaint is the internet is not working properly, is there any settings required or not? I am using Airtel net. other mobiles my beside having full signal, but my phone shows no signal. why it happening? give me reply with solution.