I cannot see a scam here.
Those PO stamps if not stuck on very, very securely, it only takes one corner to lift a little, then catching on the grey rough mail sacks they can be pilled off. I remember years ago when using our main town PO they 'proudly' stated they'd find several stamps stuck to the bottom of their grey bags when returned to them empty after collection. Dubious matter to be proud of, in my humble opinion !🤔
So, the stamp may well have come off , and it is actually a £7 excess to pay to retrieve a parcel, they are correct with that sum of money.
Now that the eBay case has closed with a refund, nothing you can do through eBay all you can do is to ask the buyer to repay you as they have the item, minus of course the excess postage they had to pay, but there's nothing to enforce them to do this.
They can repay via a bank transfer, cheque of PayPal Friends and Family payment or you can send them a PayPal invoice.
If PayPal is used, email addresses need to be exchanged, this can sometimes be found with the order details >> Show Contact Info. If not and you need to ask the seller for this, make it very, very clear in your eBay messages, as eBay do read these, the reason for these exchanges. Make it clear it's not to be used for an off eBay sale.
@michey-boo
