Is it permissible to pay phone and internet bills from bank interest, knowing that some Egyptian banks operate according to the fatwa of Sheikh Jad al-Haq, which permits not specifying interest rates at the beginning of the transaction and their instability? And is it permissible to pay a cash amount to restore internet service that was disconnected by the company, after it became clear that the branch's conditions were incorrect, using bank interest?

Investing with a predetermined interest rate in banks or investment certificates is a loan with interest, and is considered usury (riba), which is Islamically prohibited. As for investing without a predetermined interest rate, where it remains subject to profit and loss, it is permissible according to Islamic law because it falls under the contract of Mudarabah (profit-sharing). Therefore, if banks deal on the basis of a loan contract with interest, their dealings are usurious. However, if it is on the basis of Mudarabah and without guaranteeing the capital in case of loss, then it is permissible. The interest from usurious banks must be disposed of by spending it on the public welfare of Muslims or on the poor, and it is not permissible to benefit from it personally.