you need to use the same paypal email as you first did for them to add the addons to the correct scapebox account.
they do not allow you to change the paypal info from the pass, as they are always getting hackers trying it on.
if you lose your paypal account i am sure unless you got solid proof your also lose your scapebox account, and have to buy the lot agin.
you have to ask there support as there very friendly.
i got all there addons and there fantastic to use.