Must the sister pay for the second semester’s bus tickets for which she rode the bus without paying, or can that be compensated for by the subscription she paid for in the first semester of the year but did not use?

If the bus subscription contract stipulates a specific period for riding, such as the first half of the year, and this period expires without the full benefit being utilized despite the ability to do so, then it is not permissible to use the subscription in the second half. This is because the subscription is a lease contract, and the rent for a lease contract becomes due upon the signing of the contract and the ability to utilize the benefit. Therefore, if the lessee does not utilize the benefit despite being able to do so, the agreed-upon rent remains due.