AITA for insulting a customer at my dad’s restaurant for making unsolicited suggestions about my hair?

I (F 22) work part time at my father’s restaurant/deli as a cashier while I’m in school. I’m mixed, so my natural hair is very thick and curly textured and since I stopped keeping it in a protective style, I like to where it out in a semi Afro. One day, a frequent customer (an old man, probably around 70) says, “you are such a pretty girl, you shouldn’t wear your hair like that. You’d look much better if you went to a salon and gotten it straightened out”. I said back to him “maybe you should have some hair before you comment about mine”. He’s old, so he’s a bit bald. He called me rude and nasty, then flagged down my dad about it. I got in trouble but I refused to apologize. My dad has also commented on my hair before. I told the customer, “I’m not trying to make it about race but my dad is an older white guy as well, and I’m not white. My hair will never be straight unless I flat iron it”. But I’m not apologizing and I don’t feel bad about saying what I said.