Is the difference between regular bank expenses and the interest granted on a savings account considered usury (riba), and what should one do to avoid it?

It is absolutely impermissible to deposit money in usurious banks because they use deposits in their usurious transactions. This is only permissible if a person is compelled to do so out of fear of loss and cannot find an Islamic bank, in which case they may place their money in a current account without interest and pay a fee to the bank.

As for savings accounts in usurious banks, they constitute a usurious contract, and their returns are forbidden usury (riba). One must repent, withdraw the deposit, and dispose of all the interest by giving it to charitable causes.