Why did i need to pay the shipping cost again?

As the shipping cost is paid when confirming your order ( unless in some cases in which the customer decides to use her/his own freight or carrier ),  you will not be asked to pay it again for the same order. Sometimes it happens that a customer is asked to pay for custom fees before withdrawing his/her order.
Please remember that any additional custom fees should be borne by the customer accordingly to her/his country tax regulation and it is totally different from the shipping cost.