Airtel — outgoing calls and messages been barred while my phone is in international roaming

Hi team,
My mobile number is [protected]. I have changed this number from post paid to pre-piad last month.

Now, i am receiving all otp messages from banks.
But, my out going calls and messages been barred.

I am out of india at the moment and not returning for a longer time.

I have more than enough balance in my account. Not sure why outgoing calls and messages been barred. I am not able to call 121 or 1800... Customer care numbers as well. All outgoing calls been barred.

Can this issue be resolved asap.