Is it permissible for male and female students to marry before graduation without their parents' permission, especially if the father's refusal is for illegitimate reasons? And is it valid for the guardian of the Muslim Students' Association to marry off the girl in this situation? And how should one who married in this manner deal with the situation?

A Muslim woman is not permitted to marry without the permission of her guardian (wali), for "there is no marriage except with a guardian," and "any woman who marries without the permission of her guardian, her marriage is invalid." Allah has commanded guardians to marry off those under their guardianship and not to prevent them from marrying. If a guardian refuses to marry off a woman under his guardianship without a legitimate religious reason, the guardianship transfers to someone else after the matter is referred to a Sharia judge, for the ruler (Sultan) is the guardian of whoever has no guardian. If a woman marries without a guardian, her marriage is فاسد (irregular/corrupt), and separation between them is obligatory. Children born from such a union are attributed to the husband if he believed his action was permissible. However, if he knew the marriage was invalid, they are attributed only to their mother. Among the harms of such a marriage are the loss of the woman's rights and the lineage of the children. To rectify the situation, the guardian must be openly informed of what happened, then the marriage contract must be re-contracted with his consent, otherwise, separation between them is necessary.