Account blocked , how to retrieve the password ?

Hi Friends,

My Service tax account is showing as blocked when I am trying to log in to file the return.I dont know the answer to security question as well, as earlier I used to get the Service tax Return filed through a Chartered Accountant's office .But from past two years, I am doing it myself.

Now the problem is that, the accounts is blocked, Security question and answer is not there, and e -mail id in registration certificate is also not under my control.

Please provide a solution for this problem as I have to file the return and due date shall be approaching very soon.