Airtel — poor network airtel!!!

I am experiencing a huge network issue. Even tough signal is showing as full i am not able to call. Getting error server unreachable. I don't understand the real issue with airtel tough i am staying in mumbai/pune metro city i am still facing network issue in making calls. When it comes to internet this is another hell i see it is 4g on display but net speed is slow than 2g. If you can't provide good internet pls don't advertise about it. Stop fooling customer. Planning to switch from airtel. Very disappointed with network service