Having failed to pay rent for three (3) months, the lessor demanded that the lessee pay the back rentals and vacate the premises. Afterwards, the lessor filed a complaint for unlawful detainer. The lessee contends that the lessor refused to accept the rents. Is the contention of the lessee a valid defense to release him from his responsibility to pay rent? What should have been the action by the lessee to release him from responsibility?