What is the ruling on selling mobile phone top-up cards at an increased price in exchange for deferred payment, and is this increase considered usury (riba)?

It is permissible to sell mobile phone recharge cards in installments for a price higher than their cash price. This is not usury, as it is a sale of a benefit. This is called "Tawarruq" if a person buys the card to sell it for cash to someone other than the original seller, in order to obtain money. For this to be permissible, the buyer must take possession of the commodity and sell it to someone other than the original seller. It is forbidden to sell it for cash to the same seller from whom it was bought on credit, as this is the forbidden "Bay' al-Inah" (resale to the original seller). It is also forbidden to leave the card with the seller and authorize him to sell it, as this is organized Tawarruq, which is a trick to legitimize usury. It is not permissible for the office to take 50 Riyals as a brokerage fee in addition to the profit from the sale. In summary: It is not permissible for the office to buy the cards from the one to whom it sold them (Bay' al-Inah), and it is not permissible for the buyer to leave them with the office and authorize it to sell them (organized Tawarruq).