You will receive more help if you include a picture of the wall as installed and a picture of what you wanted it to look like.

did you specify shiplap? those boards are not. shiplap is specifically milled with a rabbet joint in order to overlap, producing 'the gap'. those look like regular TG pine boards, which are meant to fit snugly together by interlocking.

Shiplap ( v rustic ) often comes with shamfer on one side forming a v when the boards are put together ( like the door in your pic ) . Often the backside is squared giving a look like your wall when boards are put together. I like both ways . It's important to view the design before application .

I used the V side for the ceiling in this pic and the square side vertical for the wall.

Alex.

The best Garden Studio in palo alto · More Info

The best Garden Studio in palo alto · More Info

Yikes. This has to be taken out & done correctly. They should have looked it up if they didn't know what it was.

Did you show them the picture before they installed it? Thankfully, I was on site when ours was about to be installed because my contractor got the wrong boards. I think a lot of folks think they know what you're talking about, but without a picture it's often not the same concept. Good luck!