First, be sure to keep a copy of the terms stating the cancellation date. Secondly, I have found many properties do not charge my card until the day of or day before arrival. Rarely do I see a charge immediately following a reservation.

My guess is the person loading the rates is selecting text that they have used before and may only make additions without regard for what is already there. If there is a conflict in terms, generally the most lenient terms will apply, although you may have to argue your case if they don't do that to begin with.

In this case, IF they do charge at time of reservation and you choose to cancel in time, they should refund to your credit card. If not, dispute the charge and show your confirmation stating the later cancellation date.