Is the interest earned from the balance in a commercial bank-issued card considered usury (riba), and what should I do with this interest?

To know the ruling on Visa cards, please refer to Fatwas No. 31458 and 31397.

It is clear that the deposit operation in a commercial interest-based bank is an interest-bearing loan in exchange for time, because you gave the amount to the bank with this intent. For contracts, what matters are the intentions and meanings, not the wordings.

You must change this account immediately, and you are only entitled to your principal, as Allah Almighty says: "But if you repent, you may have your principal – [thus] you do no wrong, nor are you wronged" [Al-Baqarah: 279]. You should dispose of the excess by giving it to various charitable causes, because you are not entitled to own it.