Airtel — canceled network connection without giving any prior information

Address:

635751

All of sudden received sim card registration failed message and network connection lost, trying to call from other sim card and tried to explain, but they are responding to call from same number. But how am suppose to call when there is no network at all.
And secondly customer care number is not getting connected, 1 out of 10 times it is connecting and that time also they are not fixing it.