Is it permissible to keep a contract for haram investment certificates for three years without breaking them, and are we obligated to return the large profits we obtained from them, and should the Zakat previously paid be deducted from the expiation if it is due, and are the charities paid from personal expenses valid?

Investment certificates with a fixed return from an interest-based bank yield usurious returns. It is not permissible to keep them or to benefit from their interest. The deposit must be withdrawn to terminate the usurious contract. The obligation to repay any interest received is not an impediment; rather, it is closer to fulfilling the words of Allah Almighty: "And if you repent, you may have your principal – [thus] you do no wrong, nor are you wronged" [Al-Baqarah: 279]. This is because the total amount received, along with what is recovered from the remaining sum, will constitute the full principal. The Sharia-compliant alternative is to invest the money in a permissible manner or to place it in an Islamic bank. The zakat on this money is obligatory on its permissible principal, not on its usurious interest, and it is to be paid from the principal. As for giving charity from one's expenditure, it is acceptable if it is lawful, and unacceptable if it is unlawful. However, a person is rewarded for abstaining from the unlawful.