Mother Wants No Relationship

I know according to the Torah, we are supposed to obey our parents. But does that mean that if they do not want to have a relationship with us, we are required to respect that wish and not ever contact them?
I am adopted. My adoptive parents gave me a very nice upbringing. But they have both died. I did a DNA test earlier this year. My biological mother was not on it, but I found a biological cousin. My cousin wasn’t very welcoming but told me who my biological mother is and gave me her phone number but warned me that she would not warm up to me.
I called my biological mother. As my cousin told me to expect, my biological mother was rude to me. She spoke for under two minutes in which she admitted she had me and gave me up and said that’s how she wanted it to be. She acted like I violated her by calling her as a stranger. And before slamming the phone, she told me never to call her again.