Airtel — Bad network services

Iam a Airtel subscriber for many years now, since last 8-9 months i am facing with call disconnection problems both incommnig and out going, it just disconnects in 2-5 seconds, i am not able to make a full conversation ever, i have logged complaints to the Airtel CC, but this have only one thing to say, i.e we have taken the note & the issue will be resolved in 48 hrs, that's it, i have changed my sim card to 32bit/kb whatever, i was asked earlier, i have also changed 10 cell phones of different makes, it just dosen't work., worst is when iam driving, this is with full network shown on the cell.I keep on receiving their calls every now and then if iam having any problem, i have to give the whole explanation every time, now i have stopped using the airtel for making calls, just using it for incomming, that too if it does not disconnect., and bought a new service, i cannot discontinue the service as all my old clients have this no. I dont know how to resolve this problem, There is just no support from Airtel.