How do I get hold of a buyers email address? OR resend an invoice?

[Wilkiepedia]

I have cocked up - my old email address was sent on my original invoice so three buyers have paid to the wrong email address and it hasn't gone through.

The only way to resolve is for them to cancel payment and me to resend an invoice with correct email add.

1. I can't see how to resend an invoice other than through PayPal

2. I need their email addresses to send a PayPal invoice

Am too embarrassed to contact them again to ask for email address and I am sure there is a way of getting it through email??

Any suggestions?