Send it back as many times as it takes to get it the way it is suppose to be. We should not care how many times or how many hours it takes them to get it right. They have bean counters to worry about their bottom line and when the costs get prohibitive, maybe assembly guys will improve. "In the old days", the assembly guys were paid by piece work. The gun was fixed by the guy that built it no matter how many times he had to work on it.