I purchased airtel sim from rajasthan I network was good there then after some time shifted to calicut and for some time it was getting good network but roaming I have to pay it, but after 3 months it was not receiving any network I called customer service I told them that I was not getting network in my airtel sim for 2 days they told me they deactivated it, they told me take 4g sim, but they did not mention the reason, they told they do not know very poor customer service by airtel then I asked for free sim but no reply very disappointed by airtel so I have to throw my sim and purchased vodafone sim.