Abn Amro — credit card final settlement

Address:

Chennai, Tamil Nadu

Hi. My name is geetha ashok.
I received a call from phoenix trust on behalf of abn amro asking for a full and final settlement for my credit card (Which i already paid years back) to get a closure letter from the bank, which is taken over by kotak mahindra now. I got contacted by an advocate named suresh saying he will negotiate with the bank regarding this, since i've already paid once. I went to their office and paid the remaining money through a cheque on 15th march 2018, and i have the transaction id as well. The money is debited from my account, and i am yet to receive the letter.
And two days back i again got a call asking when i'm going to pay the amount.
If this is how its going to be, i won't think twice before going to the consumer court, and i have friends in media who would be very happy to help me.
Awaiting your reply at the earliest.
Thank you.