American Express Credit Card — Cancel my card !!

Address:

Mumbai City, Maharashtra

I am Dipen Trivedi . I have called ammex services 5 times. I kept requesting them to cancel my card and agreed to pay the amout due. After making all the payments on time I always have a new bill amount that stands outstanding. They always asked for a reason so as to why I wanted to cancel my card where as the card termination rules clearly mention that I can cancel my card at any point of time without giving any explanations. On calling the 6th time today, I still have an outstanding amount and they still say that my card will be cancelled after I pay the amount due. I really need to know why is this happening and need to get rid of this card.