(4)(a) If the prospective tenant does occupy the dwelling unit, then the landlord must credit the amount of the fee or deposit to the tenant's first month's rent or to the tenant's security deposit. If the prospective tenant does not occupy the dwelling unit, then the landlord may keep up to the full amount of any fee or deposit that was paid by the prospective tenant to secure the tenancy, so long as it is in accordance with the written statement of conditions furnished to the prospective tenant at the time the fee or deposit was charged.