As a maintenance operator in our city's sewer department, I get to deal with the public on occasion. If a main plugs and backs up into someone's home, I can understand their frustration and sympathize with them. Most of the time, they seem to just need someone to listen while they vent. As unnatural as it is for me, I just shut my mouth and let 'em blow their steam. I verbalize my understanding and tell them that I am doing what I can to alleviate their problem. Most of the time, they're a lot less angry when I leave. Someone heard them! That's what they want. They know things go wrong. I have had more people thank me for my prompt response to their call. If I get called out during off hours, I check and see if there is a backup. If they've left a phone number, I call them right away and tell them that I found thee problem and am going to get the Vactor truck to jet the line and open the plug. They want to be communicated with, not feel like they're left hanging and wondering. I don't blame them.
It's the ones who have a problem with their service line from their house, which we don't deal with, and insist that the main's plugged that I'd like to smack with a 2X4!