Reducing or cancelling a PO line that has already been billed and paid.

We have a problem scenario that we are not sure how to fix.

A PO line was generated for part A.

Line was received, invoice matched, and paid via check.

After payment it was discovered that the part number was incorrect and it was actually part B.

We want to return the receipt of part A back to the supplier, cancel the line for part A on the PO, add a line for part B, receive it and match it to the payment that already happened in the past.

Is this possible?  Can someone walk us through the steps on the AP side?  The receiving and PO side steps are obvious to us.