When I was a younger (and not as wise) man, I cussed out a few CS workers, not realizing that they were only doing their job and I was not helping myself. These days I use a method I learned from listening to my wife on the phone. Whatever the subject of the call, I pick three points I want to make, and I say nothing BUT those 3 points over and over. I'm not belligerent, but not pandering either. After a short time the CS person realizes that they have a "not-too-bright" but very persistent person on the line and they start trying their tricks. At that point I add, "I realize that you are just reading from your cards in response to my quesitons, so is there someone there who can discuss this with me?"
The other tactic for those with a foreign accent (actually I've used it successfully on some who speak perfect English), is I say few times, "I'm sorry, can you repeat that?" and "I'm sorry I can't understand what you are saying". Then I ask to speak to someone else.
It takes time but about 8 times out of 10 I eventually get someone on the line who does what I ask. AND, it's actually more fun than just getting pissed and cussing at them.