Where did you hear that its not for 1 ways?
T&C: Earned Free Rental Day coupons may be redeemed to cover base rate (Time and Mileage) only for a rental day but does not apply to taxes, fees, surcharges, refueling, drop-off, delivery, youthful driver, additional driver, pick-up, or
one-way charges or any optional product or service, which are the responsibility of the renter.