Axis Bank — debit interest on credit card

My name is asiya. I am using axis credit card since july 2017. Bank is charging interest on the whole of the amount after due date even if i pay partial due amount within the due date. Why should a customer pay the interest which already has been returned to the bank. This is happening in every statement though its been hardly a month. The bank is saying even if a penny of due amount is left to pay within the due date then the interest will be charged for the whole amount..