How soon should new timber bifold be stained/painted?

Hi all,
From recent posts you can probably tell I had a bifold door installed at the end of March. A week later or two later we got some rain and I asked the builder if the door will be okay if its soaked in its natural state. I had noticed some water marks showing up on the top and bottom of the WRC frame. He said some rubbish about it been ok to withstand the elements and that the water marks would 'dry up'. Well its over a month now since it was installed and the water marks are still there. Since it was installed some bricklaying had taken place and I also noticed on either side of the door some cement had dripped onto the wood and now shows up as a dark patch.

Should I be worried? I spoke to the manfacturer today and they said WRC should be stained/painted ASAP after installation.

I was told that oxalic acid will remove the water stains. Can someone verify this?

I am so annoyed that my new door has been weathered because of the builder's ignorance. At the moment they are trying to get some odds and ends completed ready for lockup stage, so i don't think they had any plans to stain/paint the door until Fixture/Completion stage.

Thoughts?

Cheers,
Ray