Is boycotting relatives who are unjust to the questioner's rights, including the mother, considered forbidden (haram)?

Maintaining kinship ties (Silat al-Rahim) is obligatory, and severing them is forbidden. This obligation does not cease due to a relative's sinfulness (fisq) or injustice, unless it involves assisting in falsehood or causes harm. Parents, especially the mother, have immense rights, and it is impermissible to sever ties with them, regardless of their condition. They should not be obeyed in disobedience to Allah, but rather, they should be enjoined to good and forbidden from evil with gentleness and politeness. It is obligatory to accompany them with kindness, even if they command shirk (definition) (associating partners with Allah).