Make notes to call you 1 hour before your time frame. Make sure they note it that you will meet the technician at your house. Unfortunately not all techs are this diligent but I always call all my am's at 8 and pm's at 12 to let them know approximately what time I will arrive and that if they need to run out I will call them when I leave the job prior to theirs. Sounds like you got a raw deal but really it's sticky situation. Like I said, for all we know he was running around trying to find the equipment you need but gave up 3 hours into your window.