The Change of address shall be effective only if the order has not been shipped at the moment of making the switch (status "In Process"). Obviously the address can not be modified when the order is in transit. See diagram:
1 Change of address.
2 First Monday following the Change: Label Files for shipments are generated.
3 Wednesday following: Orders are shipped according to the previous Monday file.
4 Delivery in the recipient's address.
How to change your Delivery Address:
1 Go to My Account
3 Edit the address you want to change and modify details.
Warning! No need to change the position of Address by Default. Yes means this will also be the billing address.
4 Click on Continue