Tata Docomo — I'm complaining about their cdma withdrawal and forcefully changing number

Address:

Kolkata, West Bengal, 700007

I am using tata docomo cdma walky number from last three years and now they are shutting down their cdma service. They are changing our number to gsm service. As we are having an corporate number, we have requested to keep our number same but they have denied for this services which is going to put us in trouble because our old number has been given to all of our customer.
Even they are charging unnecessarily for new gsm walky for no reason and when i asked them what about the cdms walky which i have already purchased before? They said that will be no longer in use.