Post Box out of order

It's surprising what one can come across on a cyce ride. This shiny new post box caught my eye and I went back for a closer look. I've never seen a brand new one before.

The notice on the adjacent post apologises for "any inconvenience resulting from the theft of this post box. The box will be replaced and reopened as soon as circumstances allow".

Well, the Post Office has indeed replaced the stolen box. The trouble is that a block of wood saying "Out of Use" has been wedged in the opening and is preventing anyone from posting their letters. 

What a puzzle!