Airtel — not able to make out going calls in roaming

I am unable to make outgoing calls in roaming. I am receiving incoming calls alone. My mobile data also does not work. Please resolve issue asap. I am using a telangana number, in karnataka since a month. Now suddenly today, i am not able to call from my phone. I am however able to receive calls. Mobile data also stopped working. Only wifi works.
When i try to make a call, it gets dropped off within seconds. Why does this happen to my phone. Can you resolve this issue immediately, as it is very important for me to make outgoing calls.