Seller is responsible for getting item to buyer.
Buyer should open a Not Received Case (in More Actions) you have to refund within 8 days through the case. Isuggest you tell the buyer to open a case and that you will refund, but allow a few days as delivery may just be delayed. Doing it properly means that you get the selling fee refunded.
You when able, then make a claim on RM.
Your POP is just that proof of posting, if it was a package there will be a 16 digit tracking code which you should have entered when marking as dispatched. The POP is to support a claim on RM, it is really of no interest to the buyer.
