Scammers use weakness in eBay UK’s return policy
Scammers will always find ways to exploit weaknesses in the system. eBay is allowing the use of Royal Mail tracking service to deliver to the seller’s postal code (and not requiring the the address nor signature of the seller) in order to initiate a refund. Sellers are victims in this situation and eBay is allowing buyers to run this scam on a systemic level.
The other return options in the UK exist using DHL, UPS, and FedEx. If the item value is above say 100£, requiring a return method that includes signature or verification to the address level will go a long ways to protect the seller and discourage scammy buyers.