automatically bother customer de-activate deactivated faqs forum fraudulent link notify order paypal purchase react refund reversal she software worries

I'm sorry to bother you with this, but I couldn't find it in the FAQs and Forum; I have a customer who says she didn't order our software and that someone has made a fraudulent purchase with her card. Is it possible to de-activate a link that has already been sent? If not, no worries. Just curious how I should react in a case like this. I did notify PayPal.

The link gets deactivated automatically in case of a refund or reversal.