The other side will either know the NATO alphabet or be able to understand it anyway. It was designed to be interpreted and used by non English speakers, since most of NATO doesn't/didn't speak English. I've used it dozens of times, zero errors.
It's really good enough to be considered a sort of spoken language Golay code.
^---- yes, this is exactly it. Especially since most CSRs you're going to be talking about don't have English as their first language and don't have the same cultural background as you.
That's why the people I know who use it at work don't use it while on the phone with Comcast.
