Is it permissible to deal with Islamic banks that acknowledge the existence of commingling in their transactions, with the aim of supporting the truth and hoping for future change?

If bank owners admit that some of their transactions do not conform to Islamic law, then it is obligatory to avoid them. This is because dealing with usury (riba) is one of the greatest sins, and Allah has warned those who engage in it with a declaration of war from Him and His Messenger. Therefore, it is not permissible to deal with someone who admits to the presence of usury in his transactions under the pretext of helping him.