One Hour AC Tech Broke my AC Unit

We have been using One Hour AC to service our AC unit for years now. We scheduled a regular maintenance/service for today, and the technician told us it would take 20 minutes. It has been 6 hours since they showed up, and now my AC unit will not turn on, thermostat is off too. At first the technician thought he blew a fuse, but then another technician from One Hour AC showed up and now they don't know what the problem is. My AC unit was working perfectly fine before these clowns showed up, now it's hotter than hell in my house. I called the service supervisor and he said if they are not able to fix their mess, they would replace the unit for free. Now I'm sitting around waiting for the service supervisor to show up so he can troubleshoot. Anyone deal with this type of issue before? Any advice? Thank you