Rediffmail — my account is hacked

Website:

www.rediff.com

I have rediffmail with email username: k.[protected]@rediffmail.com. Yesterday i was trying to access my email id for some of my personal work but as entered my username and password page say invalid combination, then i tried to reset my password using the tab forgot password but what i found is that my recovery email and phone number was changed without my knowledge. Now i am unable to recover my rediffmail. Also tried to contact customer care support but they asked me some questionn like "last 5 email address contact you used", "Last 5 emails you received". As i am a student and not a regular email id user, i access it either once in a week or in 15-20 days, but i still replied upto my knowlegde. Now i am waiting for the rediff's reply. Also i have addded my brother's email abhineet.[protected]@gmail.com for recovery but now as i see recovery email has been changed by the hacker. And all this happened on 5th July 2019 and still has rediff not replied for the email and not taken any action as of yet.