PO has wrong vendor, made it all of the way through invoice before anyone noticed

So I have an interesting problem that was just brought to my attention. Purchasing made a PO and chose the wrong supplier for the PO. (both of the vendors start with Brown-). He then printed the PO, and e-mailed it to the “correct” vendor. The vendor took the PO, didn’t say anything, sent the materials, they were received by PO number (I’m sure with mass receipt), no one noticed that the names didn’t add up. The vendor sent us an invoice, and the invoice was posted (still no-one noticed). Finally, when the checks were about the get cut, accounting noticed that the vendor on the PO and the Invoice don’t match :man_facepalming:

The invoice was reversed (so now there is a negative to offset, since we aren’t paying the wrong vendor). What’s the best way to fix this? I’m playing around in Pilot and while I can re-open the PO/Line/rel, It doesn’t let me change the supplier.

Is this one of those things that we just have to do a misc invoice to the correct vendor and then somehow write off the invoice that Epicor says we need to the wrong one?

Any help would be appreciated.