I had the exact same feeling.
I immediately went downstairs and found 4 tan arches in my bin (from Market Street 10190) to replace them.
I wrote an email to Lego this morning explaining the problem (piece not matching instructions/box picture/inventory, windows falling) with a picture.
Just to inform them about the mixup...
They replied 1 minute later, saying they were shipping the right pieces.
Wow, really good service.