What is the ruling of Islamic law regarding the position of a father in the sight of Almighty Allah if his ex-wife prevents him from seeing and having custody of his daughter, despite his resorting to the judiciary and his efforts to take her in, especially with her academic and living conditions deteriorating under the mother's care?

The default is that custody belongs to the divorced mother if she is religious, well-mannered, and has not remarried. Scholars have differed on the age at which a girl's custody ends, and the preponderant opinion, in our view, is when she reaches seven years of age. Since the court has granted custody to the mother, you must monitor your daughter's condition and guide her behavior according to Islamic law, and fulfill her needs for maintenance and clothing. There is no harm in trying to appease the mother to relinquish custody, such as paying a sum of money or mediating through someone who can influence her.