What would you do about this hospital volunteer?

My grandmother went in for a very high-risk hysterectomy today. Only one person was allowed in at a time in post-anesthesia recovery. My grandfather came out and told me to go in. I went to the desk and asked the volunteer to go inside, because I had to be escorted. She told me she was too busy to help me, and that I should come back when she wasn’t so busy (the phone was actually ringing quite a bit).

What would you do? How might your feelings be different if it was a paid employee and not a volunteer?