FB and Insta voided purchase AFTER I fulfilled it

I fulfilled a sale that was from FB or Instagram that said payment not captured but was guaranteed by FB or Insta and may take longer to receive, but again, was guaranteed.

I fulfilled it and then Shopify said that FB and Insta voided the transaction. Now I have an item that I have confirmed delivery of and no payment.

I cannot figure out how to get any kind of seller support, I can only get customer side order support.