What must one do who paid 70 riyals as expiation for an oath, which is feeding ten needy persons, then discovered that the expiation is 100 riyals?

The expiation for an oath is feeding ten needy persons, or clothing them, or freeing a slave. If one is unable to do so, then they must fast for three days. The feeding must be from the average food of the people, and its measure is a mudd of food for each needy person (approximately 750 grams of rice). It is preferable to make it one and a half kilograms to avoid divergence of opinion. It is not permissible to pay the expiation in monetary value, according to the majority of scholars. If the charity organization commits to feeding the needy, then paying them is sufficient. However, if they do not commit, then the expiation must be paid by directly feeding the needy.