Tata Docomo — outgoing call barred due to non payment

Hi,
I am using tata docomo [protected] from morethan 5 years.
All my out going calls and messages are barred from my number without my request.
This is ridiculous.
When i called customer care, they say i requested for call barring which i have never done. I do not get proper response from the customer care, they act so irresponsible.
I want port my number to other network which provide better service.
But i am not able to port the number as the outgoing messages are also barred.
Please help to resolve the issue asap.