[mothered]

Also cheers for the comforting words.

You're most welcome.

Wouldn’t paypal rule in favour of me if the package is marked as delivered? I’m planning on using that and putting some sort of weight in it.

PayPal do tend (at times) to rule In favor of the buyer based on the tracking being shown as delivered, however that's not the Issue In this case.

The problem Is the seller checking the return, and Identifying that the original Item has not been sent back. The seller can then file a dispute through PayPal Seller Protection and ask the transaction be reversed.