Performance Notification Regarding Product Authenticity

I sell used books FBA. I have listed over 4,000 books. I received a performance notification regarding the authenticity of a single book. As a result, I cannot list books at this time.

The notification requests invoices from a supplier, but I purchase books from estate sales, so I do not have a supplier. I deleted the item at issue from my inventory.

What is the best way to reinstate my selling privileges? I called support, and they stated that performance notifications cannot be resolved over the phone.

Any information is appreciated.