Facebook.com — hacking my fb account

Dear team,

My account had been hacked many times from some one in last 2 month. Several times a have recovered my account after hacked my account. Some buddy hacked my rediffmail account and using that one to hack my fb account. As of now my rediffmail account is still hacked by that person. My information leaked from fb only like my rediffmail email id. I want to know that from where my account had been hacked. Last i remember tried on 20th july 2019.