How can CashU amend its savings program—which is based on certificates of deposit and investing the collected funds in the company's electronic products with the calculation of profits and rewards—to be compliant with the provisions of Islamic Sharia?

This investment is forbidden because the profit is a percentage of the capital, which invalidates the partnership Islamically, and makes it an interest-bearing loan if combined with a capital guarantee. To correct the contract, there should be no stipulation for a capital guarantee, and the profit should be a percentage of the actual company profits, not of the capital.