personally i’d wait till it arrives then make payment again, after checking its not already gone through.
sorry reread that and it sounds likes it arrived already, speak to paypal, see what they say. At this point a rogue would keep the bag and paypal would side with you, as the seller shouldnt be posting until payment is received.
I think payment can be rejected if the recipient’s PayPal account isn’t properly set up. Email not verified, or no funding source linked, etc. I assume you’ve asked the seller why they refused it, maybe ask if they have received other payments successfully?
Is it a new seller? Could be they haven’t set up the account properly or just cocked up.
I’d get them to send you an Invoice via PayPal (not friends) for the payment.
Had something similar on a new seller, I paid but payment never collected (they registered PayPal email wrong, email ended couk and not co.uk). I’d received the item and as described. Checked with PayPal there was no way the first payment could be collected and they assured me there was not.
Ebay/PayPal said only option to pay was a new listing/cancel original listing or PayPal invoice.