How can I get a PDF copy of my receipt?

I'm the customer, Corsair Memory is the seller. I paid for advanced RMA where customer pays upfront for a warranty replacement of a product. I received the replacement product and sent them the faulty product, and all was well. Now the replacement product has failed also, and I'm asking for another replacement. But they ask for a copy of the invoice and they say they do not see it under the e-mail address I am contacting them from. But I have not changed the e-mail address for my Corsair Help Center account that I use to contact them, and I have received an e-mail from receipts@corsair.com to the same address, with the typical Stripe template.

You're receiving this email because you made a purchase at Corsair Memory, Inc, which partners with Stripe to provide invoicing and payment processing.

I went to https://support.stripe.com/charge-lookup and provided my card number, charge amount and date, and was able to locate my payment. Why are they unable to do the same? What does it take for a company that "partners with Stripe to provide invoicing and payment processing" to provide the customer with a verifiable receipt? Why is Stripe no sending me a verifiable PDF invoice instead of just an e-mail? Can I have the invoice as a PDF from Stripe? A verifiable invoice with all the details?