Citibank — Credit card charge even after closure of card

Dear Sir,

I am a reputed employee of public sector bank. I have applied for Citibank credit card which was lifetime free and used it in 2018.I have used it only one time and made payment of it and closed my credit card in 2018. Recently I have checked my Cibil report where Citibank credit card shows Rupees 1838 outstanding balance in my account and due 700.In this Pandemic situation Bank Employees have worked in spite of corona threat to provide service to Common Man. I ask Citibank, after closing my card in 2018, how they start charging me from September 2020 to May 2021. I have never received any conservation, letter or SMS after 2018 from Citibank. My Cibil also got affected. I want apology letter from Citi bank and clearance of my this issue and no due certificate of my mentioned credit card.

My Citi bank credit card number:[protected].
My email id:[protected]@gmail.com
My mobile no:[protected].