How to get what you want...
There are times this isn't too bad of a "gig". I actually like talking to people. I also am very interested in how language affects how people relate to each other. There are some employees who do very well with certain customers, and others that just butt heads. Since the customers can't see us, it has to be the way that we speak to them, and not just the words we use. One of our people that has a real Jersey accent, has problems dealing with people from the Midwest, but our people that sound like they are from the south deal really well with the people from the Midwest.
I've tried a little experiment, and it worked surprisingly well. When I am talking to someone from Mass. or Long Island, I start talking very fast and act a little gruffer a little more short, and the customers respond really well to that, and they are actually more friendly. Then, when I am talking to someone from the south, I slow way down, use "Sir" and "ma'am", and be sure to always use more pleasantries, and they respond equally well. But the secret is not to use too much regional slang, or they will think you are mocking them. You never say "Youse guys" in Jersey, or try to drawl out a "How y'all doin' today?", because they will catch you as a fake.
As far as I can tell, changing the rate of speech, level of manners(or lack thereof in some eastern states) immediately makes you appear more trustworthy, creates sympathy and goodwill. People are more apt to do what you want.
I'm still working on my Canadian and West Coast accent-they are a little more subtle, and not so easy to pull off.