Whenever any payment heretofore or hereafter made by a state agency for work, services, materials or equipment performed or furnished under this article or any other law by another state agency was erroneous, in excess of the amount that should have been paid or was unearned, the State Controller shall, upon request of the state agency which received such payment, refund such erroneous, excess or unearned amount by transferring an amount equal thereto from the fund or appropriation credited with the overpayment to the fund or appropriation from which said payment was made.