My Codechef.com account is being used by some one else

Hello Admin,
I am Ambrish Awasthi and this codechef account https://www.codechef.com/users/astr0naut belongs to me and last time i used it at 20 Aug 2017, now when i am trying to login , it says

Sorry, unrecognized username or password

and when i see the profile it belongs to someone else . I do not know the person and doesn’t share password with anyone else. I haven’t used any public computer to login in previous month. The password for codechef account is saved in chrome.

Please Help me to get back access to my account which belong to me for two years.

You should write a mail about this to admin. He can be reached at admin@codechef.com. But the point here is why someone would hack your account as it would be of no use to him i guess so better recheck your username and password. if the problem still persists then inform admin.

thanks i will follow your suggestions.