The perfume was not sent using Simple Delivery.

You used RM Tracked 48 and, although you may have bought the label from Ebay, it wasn't Simple Delivery.

So, you were liable for the refund but can try to claim for the cost of the item from Royal Mail.  (Through Packlink if you bought the label through Ebay.)

"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)