Airtel — outgoing calls and messages

During from 30 days when iam trying to make a out going call its diretly disconnected like its showing call ended..in the mean while i contact with customer care they are saying your problem will be resolved with in 24hours.
But up to now iam facing same problem.
And the customer care said replace a new sim in place of old sim, i traied that one also.. But no use.. Worst service from airtel
And there service