Postage and other ebay pitfalls. : eBay Guides

I am a new ebayer of four months experience. I am a seller and a buyer and I am a victim. For the last few months I have been happily sending items out to buyers, informing them that I have sent them and recieving a reciept of postage from the post office. Recently I recieved a complaint that an item had not arrived. As it was the Xmas period I asked the customer to wait. After a few days when it had still not arrived I suggested to my now anxious customer that they should buy a replacement. I would send this by either ecorded or special delivery and they could then return one of the two that they did not need. I would obviously give them a full refund once the item was returned. They asked me to send another but would not pay for it ( I understand there frustration) Just as we were discussing the choices available the item arrived - Hallelujah.

However it has happened again with a different customer and a different item. This time my customer has said that I have defrauded them as I have not sent the item and they are going to log negative feedback against me and claim their money back from ebay. I have offered to re-send the item, I have offered to chase Postal office and I have asked them to confirm their address. HOWEVER here is where I became a victim. The paypal terms and conditions state that I MUST HAVE PROOF of reciept.I assumed that if I offered insurance / special / recorded delivery and my buyer declined then all I had to do was provide proof of postage ie reciept from Post office.

Now I am left with several unpalatable choices. Do I re-send item to buyer (at my expense on postage and item cost and insured delivery!), refund the payment ( lose the missing item, fees and time), pursue claim with PO - lol. Or perhaps ask buyer to split costs with me. Either way It would appear that for all future purchases I either have to use recorded delivery or take a gamble!

Any advice/suggestions would be gratefully recieved.