Scheduled for a furnace tune up as my furnace has ...

Scheduled for a furnace tune up as my furnace has not been feeling at 100% and had to wait 3 weeks until the first appointment was available for any time slot. They called me hours before the service time to reschedule another day as the technician was no longer available for today. The soonest they could have someone out was another 3 weeks out. I had already had to take time off work to work around their schedule and they couldn't even do that for me for the second time around on their mistake. Very poor service.