As Brad R stated I had a similar issue with RS Andrews. I was giving an appointment time of 1-4PM on 11/19/2011 at 12:30PM I got a call letting me know they were closing the office but would be at my house before 4pm.
NO SHOW at 4pm. At 4:40 PM I got a call informing me they would be another hour to an hour to an half. The tech explained to me that he was busy removing a water line from a gas line. As the same thing with Brad, why is this MY problem I was told they would be here between 1pm and 4pm and that they would call if they were no on time. Calling 30 minutes after the appointment is not notifying you they will be late, it's confirming they are late.
I called in to the customer service line to cancel my appointment and as Brad there was no concern of any kind and I was told someone would call me back, but of course no one called me back. Perhaps RS Andrews has so many customers they forgot about good Customer Service and abiding by there own web site promises.