I can't speak to what you're doing in recording them, though it sounds interesting and I can definitely see why it would work. You're putting them on the spot, you're different so you have their attention, etc.
As to customer service I agree with you that many just don't care. The ones that do really stand out. I ordered food at a restaurant recently and the lady kept interrupting me and getting things wrong. In the end she got yet another thing wrong and when I explained that I wanted something else she got defensive and nasty. At first I tried to take the blame but when she got nasty I just up and left. In that case I had options. Often when dealing with customer service on the phone you can't just leave. So I like this idea.