Citibank — Credit card previous month dues paid but card blocked without information

Address:	Chennai, Tamil Nadu, 382001
Website:	www.citibank.co.in

I have credit card (ending with 9514) of citibank that I am using since more than past 6 Years. I have paid all the dues regularly.Citi bank service call centre reps are also accepting that I have paid all the dues regularly and some times I have paid more than due amount anticipating my next month expenditure in advance.

since last for days when my online transaction declined by Citibank, I called citi bank customer service staff they replied me that although you have paid all dues on time. Your card status is showing permanently closed in our system and gave me following phone no to ask the reason:[protected].
After calling that No I came to know that although I have paid all the amount of my card ending with 9514 card is blocked because of due amt of other credit card ending with 7085 which I never used and got cancelled as it was given to me by citicard reps free of cost. But some processing fee charges were due.
The man to which I had spoken was accepting that whatever was done was wrong and by mistake, but still refused to revoke the credit card.
He told that first I have to make payment of all dues .( My credit card payment due date is 12 April 2017.)
After payment of dues also my card will remain permanently closed I have to apply separately for revocation of my card.
It is causing grave discomfort and distress to me.
I have been harassed by citibank for no reason.
I request you to help me so that my card is revoked and Unless it is not revoked I will not pay the amount which is due on 12 April.
They should not lavy any charge and interest over that amount as their action has caused lot of problem for me.