Rabban Gamliel had no problem altering even a divine commandment to correct an injustice. That is what rabbis are supposed to do. And yet the majority of today's rabbis refuse to change this barbaric situation, in which every single Jewish woman who seeks a divorce is subject to endless extortion by her husband with the complete collusion of the Rabbinical Courts. Rabbi Moshe Morgenstern, great-grandson of Rabbi Katznellenbogen of Mezritz, brilliant Torah scholar and posek who received ordination from Torah Vada'at and Rav Moshe Feinstein, has ruled that when all other methods have failed, we do not extort a woman, or cause her to live in celibacy or childlessness because her vindictive spouse has decided to withhold her divorce. Therefore, her agreeing to marry him is a mistake.
Marriage is a contract.
The woman doesn't have to pay any exorbitant bribes. Doesn't have to track him down and beg him. He disappears, his power of evil destroyed by the good that is the Torah. It is written in a way that any intelligent person can grasp. Rabbi Morgenstern and his colleague, the great Rabbi Rackman, have performed a great sanctification of God's name by righting this wrong in halachic rulings with their court.