Messed Up

We had a new volunteer buyer for the gift shop. Our regular buyer had a hip replacement and is undergoing several weeks of therapy.
I left a message on the phone machine of the new volunteer and said she should check expiration dates of things purchased at a particular store and not get them if they have expired or are really near expiration.
Well, that made her angry. She came, went through all the stuff, paid for the expired stuff and turned in her smock and key. She also vented a bit on her sister who is the hip-replacement volunteer.
Now. It is nice to feel appreciated when volunteering. It is also important not to get hurt feelings easily. I know this for a fact.
The sister said not to apologize, she was wrong. I said to be who I am, I need to apologize for hurting her feelings. Whether she accepts the apology is who she is and I can't help that.
Anyway, today was a big mess for me. But yesterday I made a big mess for somebody else. So I apologized.