When booking at Marriott, it is very clear the dollar amount of no show fee or canceling after the deadline fee that will take place.

I believe when Hilton does not explicitly state the amount of penalty, you could have a case for a credit card dispute stating that they did not disclose to you the exact amount therefore you did not authorize the charge. Clicking you "agree to the terms and conditions of the reservation" is fine but when they do not disclose to you what the penalty fee is, I feel that your "agreement" is without proper information.

When you book under normal circumstances it is very clear: whatever the first night's rate is, you will be charged. But on a points rate that is an unknown.

I would fight this.