Airtel — not able to send outgoing sms

Address:

Chennai, Tamil Nadu, 600048

* i am not able to send the outgoing sms to any other number, which is making a big trouble in my day to day life usage of sim
* i have went to airtel service centre twice in past one month
* first time they said that we have send complaint it will be resolved by next day, but same problem extended
* second time they said that they will give me a new sim with the same number, but same problem occurs with the new sim also
* how many times i have to go to the service centre for this problem
* please resolve my problem as i am not able to do my bank trasaction because this is my registered mobile number for the bank account