My biggest, number one, everything else hinges on this customer service rule: I (the customer) should not have to call you (the service provider).
Look, if you are providing a good or service, I don't care if you're going to be late. I don't care if something went wrong. I don't care if you're delayed or if you have to reschedule. As long as you call me.
Call me and let me know you are running late. Call me and let me know that something's up. That call absolves most anything.
In other news: Ugh, hurry up Dish Network guy.
UPDATE: So, the guy is scheduled to come between 8 a.m. and noon. He doesn't show. I didn't get a call from anyone until about 10:45 telling me that they'd try to be there by noon. I wind up calling customer service many, many times until 6 p.m. when they tell me that they'd tried to call me to tell me they'd have to reschedule. Bullshit. The only time I was on the phone today was with you. I came >this< close to going with the competition. Unfortunately, the closest package through DirecTV is more than $20 a month more expensive and local cable is about $30 a month more expensive.
On top of this, they were telling us that the earliest they could come back out would be Thursday. Fucking insane. First, you bump me, then penalize me because you fucked up. I couldn't even talk to them. So, the wife talks to them a few times and finally asks to speak with a supervisor. We got scheduled to be the first stop tomorrow morning.
We'll see how this goes. What a way for a business to start their relationship with a customer.