Have you looked up the factory specs. for the string and cables?
It's kind of cut and dry, they are either the right length or they are wrong. Find the specs and measure, if they are wrong he should return your money, if they are right you need to find someone who knows how to install stringa and cables.
On another note, there are to many half ass string makers out there that put out half ass strings, Ive got burned acouple of times on junk strings. When you find a good one stick with em.