Also if you EVER used any form filling software like Roboform well there ya go. Also it may be in IE's memory for filling out a form. So indeed try to buy somthing you maybe bought before online.
Also did you delete the email? Or ever back up the email folder.
Also get "Restoration Version 2.5.14" (great free prog to recover deleted files with a search feature) and do a search. Maybe it is still sitting on the HD somewhere. Its poss. Take you 5 mins to find out. Search: epass (Bingo!)
Also get on the phone to St Kitts. Number and info here:
https://www.sknanb.com/message.htm
They can prob resend it to your email on record.