Canapé modulaire réversible Glant Furniture

I'm not happy with the quality of this manufacturer. The attached photo shows how it was sent to assemble, and this gaping hole for the bolt is for the main back structure of the couch bolted to the seat. I've had to place the sectional against the wall, because it will never hold up to someone leaning against it. I can't believe this made it out of the factory with this major flaw. Very unsatisfied.