Tata Docomo — not able to send sms

Address:

Rohtak, Haryana, 124501

I am not able to send any sms through my mobile number. It's been around months that i am not able to send any sms. Every time i phone them they say that i should change my message centre number. I tried it and even then the problem persisted. I keep calling them and they give me the same explanation everytime. That phone number is connected to a lot of my accounts and barring of outgoing sms es is creating a lot of trouble to me. Please help me out as soon as possible.