What is the legal ruling on Khul' (divorce by compensation) when coerced by the husband's abuse and withholding of rights?

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If a husband abuses his wife, harms her through beating or restrictions, or withholds her rights such as maintenance (nafaqah) or division of conjugal time (qism), compelling her to pay compensation (iftidā') for her release, and she complies, the Khul' is void, and the compensation must be returned. This opinion is narrated from Ibn Abbas, 'Ata, Mujahid, al-Sha'bi, al-Nakha'i, al-Qasim ibn Muhammad, 'Urwah, 'Amr ibn Shu'ayb, Humayd ibn 'Abd al-Rahman, and al-Zuhri. It is also the view held by Malik, al-Thawri, Qatadah, al-Shafi'i, and Ishaq. The evidence for this ruling is the verse: "It is not lawful for you to take back any of your gifts, except when both fear that they may not be able to keep the limits established by Allah" (Quran 2:229). Furthermore, there is the verse: "It is not lawful for you to inherit women forcibly, nor should you detain them in order to take away part of what you have given them unless they commit a clear indecency" (Quran 4:19). The reasoning is that the compensation was extorted unjustly, thus it is not deserved, similar to the price in a sale or the wage in a lease.