Editing collection address

Hi, I’ve just sold my first item and on going through the book a courier part. I managed to book and clicked ok without double checking and it came back with an old address to collect from! I don’t know why, because I get items d to my new, current address, so ebay know my current address!! And now I’m unable to edit the address, unable to delete it. I get a ‘cancel order and get buyer to buy again’ message, which isn’t exactly helpful! Any advice please, and it needs to be quick please, thanks