I had a somewhat easier experience with Vivendi Universal Games than Stephen described. It was probably due to the fact that I had seen his struggle with them so I replaced my usual "your product doesn’t work as expected, I would like it if it did", with the much more effective:
The hoops you make us jump true to prove our legitimacy are bad enough when they work. They are utterly unacceptable when they fail. I expect to be issued with a new [CD] key immediately and I believe I have given you more than enough information to enable this to happen.
which got me a hole in one.