The taking, receiving, reserving or charging a greater rate of interest than permitted by this chapter or other applicable law, either before or after the interest may accrue, when knowingly done, shall be a forfeiture of the entire interest which the note or other evidence of debt carries with it, or which has been agreed to be paid thereon. And in case a greater rate of interest has been paid, the person or his legal representatives or corporation by whom it has been paid, may recover back twice