I am so sorry to hear about this. To respond, we have a full staff and take time to make sure each of our clients is taken care of, and as all of our machines have lifetime warranties, the situation you've described does not seem like our usual practice. If you can respond by contacting us directly with the serial number of your device I'm sure we can get your machines back up and running.
We don't actually perform repairs in our corporate office, so employee turnover would not affect our return / replacement policy: the machines are upgraded in England at the Nova Science Institute by our factory technical crew using very strict assembly and quality control techniques.
I also do not know why a screw would be missing... Checking for a missing screw is one of the ways The Nova Science Institute uses to detect if the machine has been opened or tampered with, which would of course void any warranty, and they're very careful to make sure that all screws are present when the machines are shipped.
Due to the price of our machines and the long-term view we take with our clients, we attempt at all times to be as accomodating as possible. If you are continuing to have issues with your machine I would be happy to speak with you personally to make sure that you are properly taken care of.
If you have any questions please call me directly,