Wow! Sure sounds like someone is guessing at the problem and making the customer pay for it all. You should request a trouble shooter from your elevator company to work on it, they can generally fix problems that the average mechanic/technician cannot.

This is probably going to turn out to be something dumb that was overlooked like clipping a door lock or the safeties were never reset properly.

Roped hydros are a pain, even worse when they are poorly installed!