What is the ruling of Islamic law regarding a wife who does not answer her husband's calls for three weeks due to family problems, and is the husband considered unjust if he divorces her in this situation?

Disagreements between a wife and her husband's family are common, and a wise husband is one who can reconcile or minimize their effects. If the wife does not speak to her husband when he calls her by phone without a valid Sharia excuse, then she is disobedient (nashiz), and he should be patient with her and strive to reform her through the steps prescribed by Sharia, the last of which is divorce. The cause of the problems might be the wife living with the husband's family, and she has the right to an independent dwelling. The husband residing far from his wife might also be a cause for problems, and he should strive to have his wife with him. It is her right that he not be absent from her for more than six months without her permission.