FWIW, customer service of your average corporation is likely to already have voice fingerprinting in place.
It's not like you can't give them false information.
Also dob is frequently used as a verification. So it is kind of a big deal.
There are a couple of systems I've said "no your fucking menu options didn't change, I want to talk to a fucking human being" and was instantly connected. My thought was, "wait that worked?"
Somewhere my customer records at some company must say: "this guy really hates voice prompts, but is also very pleasant and amenable to working through a problem with patience"