Buyer is being unresonable.

[scarfworld_1]

I sold an item on Ebay and posted it on 19th Dec. I advised the buyer. On 26th Dec the buyer advised me they has not received item. They told me their local post office was opened and my item was not delivered to them. To my knowledge mail does not get delivered on a public holiday.  I do not have control over the Post Office. I think it is unreasonable for the buyer to think the item should be delivered on a public holiday when mail does not get delivered. I have never had an issue with any buyer before. The buyer said they would wait a few more days. Am I looking at this wrong? or am I missing something? Has anyone else had a similar issue with a buyer around the Christmas period?