Amazon India — Order cancellation - repeated attempts

Address:	400064
Website:	Amazon

Order number:[protected]
I had placed the order on 25th December morning and requested for order cancellation at 15:35 Hrs that same day. I was told the order would be canceled with immediate effect but the same was not taken care of and I received an email which said the order cannot be canceled. Why was this request not placed immediately?
I called again on 27th December 00:47 Hrs for re-request the order cancellation and was assured the cancellation will be taken care of by the customer care executive but I got another email which said the order cannot be canceled as it has already been shipped.
I do not understand why the order cancellation is such a hassle for such a big firm like Amazon.
This order is a gift for the person at the delivery address and this gift should not be given any longer which is why the request for cancellation. It is disappointing if the firm cannot complete such a small request which should be part of its operations. Request you to re-look into the matter and ensure the order is not delivered to the address mentioned.