What is the ruling on using a Visa card issued by a bank with a flawed banking system, which charges a proportional fee (3.5%) on transactions, given that an alternative is available with a fixed shipping fee instead of transaction fees?

Prepaid cards are permissible to use, and there is no usury involved in their issuance fees or in purchasing with them, because they do not entail a usurious loan. Rather, the cardholder withdraws from their existing balance in their account. The fees that the bank charges for these cards, whether for issuance, cash withdrawal, or payment for purchases, are permissible because they are in exchange for services provided by the bank, and no Shariah-forbidden consequence results from them. It is permissible to use them to purchase gold and other items for which immediate possession is required by Shariah, because the deduction occurs immediately upon purchase.