Tata Docomo — showing invalid sim

Hi... My tata docomo is showing invalid sim from the last few months.

I have been using the same number for my bank accounts, govt services and other other online portals. Now i am in problem as i want to retrieve the services of my current docomo number. I tried reaching the customer care but the call is getting disconnected neither am i able to connect anyone online.

Please help me out. I want the number activated again. And kindly confirm that it wouldn't been given to anyone as the number is connected with banks and different financial accounts.