A bit rough when you refund and apologise.

as for the buyer, add them to your Special" list. You can bend over backwards for some buyers but no matter what you do, they will trash your feedback because they can. 

On on the other hand you can get some buyers who are thankful and appreciative when you try to do all you can. AP recently lost one of my parcels, so I fully refunded my buyer, she was so patient, so I offered her free postage on the next item she purchases (if she was interested in purchasing from me again). Well, I received the nicest email from this buyer, saying she thought I was just the nicest, kind person!