volunteering issue as nonprofit mentor

Looking to handle this issue in getting a volunteer mentor position.

I recently contacted a mid-sized nonprofit in my region for a volunteer mentoring position. Someone very young called to quickly discuss the volunteer hours etc and said that they would send paperwork for me to fill. However, I received an email asking for a "personal reference" after the talk and saying once it clears they'd send paperwork. I find it strange and not very professional of them not to mention it during the phone chat opportunity during which he discussed many other things such as hours and when to begin volunteering. Instead of being upfront and professional about it when he knew it to be the next step, he chose to email without disclosing this on phone. Feel misled and wonder why i should invest time from my demanding schedule with such staff.

Is it usual and what if I don't give any personal reference?
I am planning to directly point this out to this staff asking what i said above. What would be the right way to address it?

I want to volunteer and wouldn't have had issue with providing reference but i am questioning the staff's volunteer relations approach and whether they respect value volunteers time etc.
I graduated many years ago and have long years in tech industry. Now not sure if getting involved with and contributing to this inexperienced staff would be a good idea.