I've had to work on making these voice recognition systems before. We originally allowed for people to just say operator pretty much anywhere in the app, and the client got upset that so many people asked for an operator and got sent to their agents that they had us restructure it so the person had to try pretty darn hard and be overly persistent before it decided to transfer to a person.
I felt a little bad doing it, especially after listening to the actual calls where people would just sound so annoyed and frustrated as they continuously asked for an operator, but the client insisted that less people actually reached their call centers.