What is the ruling on benefiting from a bank offer that returns a portion of the amount paid by a credit card, making the amount repaid less than the amount spent?

If the bank imposes an usurious interest on the amount used for the purchase, and then returns a portion of the paid amount to the cardholder, so that the cardholder pays the bank less than what they took, this is considered prohibited usury (riba) and it is not permissible to enter into such a contract. This is because the bank's return of some of the money as a "gift" does not change the ruling on the usurious transaction. The Prophet (peace be upon him) cursed the one who consumes usury, the one who feeds it, its scribe, and its two witnesses.