I phoned PP after reading your post and it is indeed the case that a receipt which clearly states the postcode is enough to prove postage, the money has now been returned to me.Thank you very much once again.x

So, you are obviously very happy with the outcome, but what about the buyer?  They paid $200 and have no item, which means they will most likely never buy anything on eBay in hurry.  All that for $3 extra for registration that you should have added to the postage, which would have made it more likely that the item was delivered.