If contractual documents are contradictory, is the contract void?

My friend signed both the Terms and Conditions as well as the Contract to rent a new apartment.  The Contract stipulates an extra $10 fee due upon termination of the rental if the laundry key is not returned, but the Terms and Conditions stipulate the $10 fee is due before the contract term begins, and is refundable upon move-out.  My friend doesn't need a laundry key, because she does laundry at her parents house less than a mile away, but they claim that there's no choice upon receiving a laundry key - everyone gets one no matter what, and the $10 is collected up front and refunded later. If the Terms and Conditions say that it's due upon check-in for her new apartment, but the Contract itself says that it's not due at all, only as a fee if the Laundry key is not returned (and nothing indicates that she HAS to receive a laundry key), then should she still have to pay?  Namely, is the Terms and Conditions just as binding as the contract, or does it have to be stated in the actual contract itself in order to be able to charge the given fee to the tenant?