Installation of faux wooden Venetians on balcony windows and door

Luke came to my flat to advise on what blinds would be suitable for my balcony window and door. We settled on venetians, having gone through the options and him checking the space behind the door to ensure that there was enough room for the door to open fully with the blinds in place. He advised that there were three different width slats. Via email later on, I asked for the widest slats. At no point did Luke flag that the widest slats would mean that the door wouldn’t open. After installation, I tried to open the door – it couldn’t open even half-way. It damaged my wall/paint when I tried. Update- I have now received a full refund from the trader.